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  • 1. Aksenova, N.A.
    et al.
    Isakina, A.P.
    Prokhvatilov, A.N.
    Strzhemechny, M.A.
    Soldatov, Alexander
    Sundqvist, Bertil
    Structural studies of C60 polymerized at high pressure1997In: Proceedings of the Symposium on Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials: : [based on papers presented at the fourth symposium of the Fullerenes Group of the Electrochemical Society, held at the 192nd Meeting of the Electrochemical Society in Paris, France, from August 31 to September 5, 1997. This symposium, entitled Fullerenes: Chemistry, Physics and New Directions X ...] / [ed] Karl M. Kadish, Pennington, NJ: Electrochemical Society, Incorporated , 1997Conference paper (Refereed)
  • 2. Aleksandrovski, A. N.
    et al.
    Kir'yanova, E. A.
    Manzheli, V. G.
    Soldatov, Alexander
    Tolkachev, A. M.
    Anomalies of the plastic deformation of solid parahydrogen1987In: Soviet Journal of Low Temperature Physics, ISSN 0360-0335, Vol. 13, no 10, p. 623-624Article in journal (Refereed)
    Abstract [en]

    The work hardening curves σ(ε) of special-purity parahydrogen single crystals are obtained in the temperature range 2-6 °K at very low stresses (σ=5 10 - 2 g/mm2). Our study reveals a number of anomalies, in particular an effect whereby a sample recovers its dimensions after plastic deformation reaching 7%. The work hardening curves of solid neon are also obtained for comparison. The gravity-induced downward flow of parahydrogen single crystals at helium temperatures mentioned in the literature has not been observed.

  • 3. Aleksandrovskii,, A. N.
    et al.
    Esel'son, V. B.
    Manzhelii, V. G.
    Udovidchenko, B. G.
    Soldatov, Alexander
    Sundqvist, B.
    Negative thermal expansion of fullerite C60 at liquid helium temperatures1997In: Low temperature physics (Woodbury, N.Y., Print), ISSN 1063-777X, E-ISSN 1090-6517, Vol. 23, no 11, p. 943-946Article in journal (Refereed)
    Abstract [en]

    The thermal expansion of fullerite C60 has been measured in the temperature range 2-9 K. A compacted fullerite sample with a diameter of about 6 mm and height of 2.4 mm was used. It was found that at temperatures below ~ 3.4 K the linear thermal expansion coefficient becomes negative. At temperatures above 5 K our results are in good agreement with the available literature data. A qualitative explanation of the results is proposed.

  • 4. Aleksandrovskii, A. N.
    et al.
    Palei, V. V.
    Soldatov, Alexander
    Parbuzin, V. S.
    Thermal expansion of solid deuterohydrogen at helium temperatures1990In: Soviet Journal of Low Temperature Physics, ISSN 0360-0335, Vol. 16, no 11, p. 784-785Article in journal (Refereed)
    Abstract [en]

    For the first time, the thermal expansion of solid deuterohydrogen (HD) is studied in the temperature range 1.2 to 5 K. The isotopic impurity concentrations are 1.5% H2 and 0.4% D2, the other impurities totalling less than 5 · 10 - 4%. It is shown that the thermal expansion coefficient of solid HD can be described by the expression [proportional]HD(K - 1)=1.38 · 10 - 7 T3 in the investigated temperature range. The isothermal compressibility ξT=(34 ± 6) · 10 - 10 Pa - 1 is predicted on the basis of the experimental results and literature data.

  • 5. Aleksandrovskii, A. N.
    et al.
    Soldatov, Alexander
    Manzhelii, V. G.
    Palei, V.V:
    Thermal expansion of solid parahydrogen at helium temperatures1989In: Soviet Journal of Low Temperature Physics, ISSN 0360-0335, Vol. 15, no 8, p. 492-493Article in journal (Refereed)
    Abstract [en]

    Thermal expansion of solid parahydrogen is investigated in the temperature range from 0.9 to 5 K. The content of the orthomodification in parahydrogen is 0.13 at. %, and that of nonhydrogen impurities is less than 2 10 - 3 at. %. No anisotropy in thermal expansion was observed within the experimental error. The temperature dependence of the linear expansion coefficient can be described by the expression α=1.82 10 - 7 T3. The obtained values of α are in good agreement with the available data on compressibility and ([partial derivate]p/[partial derivate]T)V. The Grüneisen coefficient is γ=3αV/CV`T=2.00 ± 0.25.

  • 6. Alexandrovskii, A. N.
    et al.
    Esel’son, V. B.
    Manzhelii, V. G.
    Soldatov, Alexander
    Sundqvist, B.
    Udovidchenko, B. G.
    Thermal expansion of single-crystal fullerite C60 at helium temperatures2000In: Low temperature physics (Woodbury, N.Y., Print), ISSN 1063-777X, E-ISSN 1090-6517, Vol. 26, no 1, p. 75-80Article in journal (Refereed)
    Abstract [en]

    The thermal expansion of single-crystal fullerite C60 has been studied in the range of liquid-helium temperatures (2-10 K). At temperatures below ~4.5 K the thermal expansion of fullerite C60 becomes negative, in agreement with the previous results on polycrystalline materials. A qualitative explanation of the results is proposed

  • 7.
    Allali, Naoual
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. LCPME, UMR CNRS-Université de Lorraine, Villers-lès-Nancy, France. SRSMC, UMR CNRS-Université de Lorraine, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, France.
    Urbanova, Veronika
    LCPME, UMR CNRS-Université de Lorraine, Villers-lès-Nancy, France.
    Etienne, Mathieu
    LCPME, UMR CNRS-Université de Lorraine, Villers-lès-Nancy, France.
    Devaux, Xavier
    IJL, UMR CNRS-Université de Lorraine, Nancy Cedex, France.
    Mallet, Martine
    LCPME, UMR CNRS-Université de Lorraine, Villers-lès-Nancy, France.
    Vigolo, Brigitte
    IJL, UMR CNRS-Université de Lorraine, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy Cedex, France.
    Adjizian, Jean-Joseph
    IMN, UMR CNRS-Université de Nantes, Nantes, France.
    Ewels, Chris
    IMN, UMR CNRS-Université de Nantes, Nantes, France.
    Öberg, Sven
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    McRae, Edward
    IJL, UMR CNRS-Université de Lorraine, Faculté des Sciences et Technologies,Vandoeuvre-lès-Nancy Cedex, France.
    Fort, Yves
    SRSMC, UMR CNRS-Université de Lorraine, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, France.
    Dossot, Manuel
    LCPME, UMR CNRS-Université de Lorraine, Villers-lès-Nancy, France.
    Mamane, Victor
    Institut de Chimie de Strasbourg, UMR CNRS-Université de Strasbourg, Strasbourg, France.
    Accurate control of the covalent functionalization of single-walled carbon nanotubes for the electro-enzymatically controlled oxidation of biomolecules2018In: Beilstein Journal of Nanotechnology, ISSN 2190-4286, Vol. 9, p. 2750-2762Article in journal (Refereed)
    Abstract [en]

    Single-walled carbon nanotubes (SWCNTs) were functionalized by ferrocene through ethyleneglycol chains of different lengths (FcETGn) and the functionalized SWCNTs (f-SWCNTs) were characterized by different complementary analytical techniques. In particular, high-resolution scanning electron transmission microscopy (HRSTEM) and electron energy loss spectroscopy (EELS) analyses support that the outer tubes of the carbon-nanotube bundles were covalently grafted with FcETGn groups. This result confirms that the electrocatalytic effect observed during the oxidation of the reduced form of nicotinamide adenine dinucleotide (NADH) co-factor by the f-SWCNTs is due to the presence of grafted ferrocene derivatives playing the role of a mediator. This work clearly proves that residual impurities present in our SWCNT sample (below 5 wt. %) play no role in the electrocatalytic oxidation of NADH. Moreover, molecular dynamic simulations confirm the essential role of the PEG linker in the efficiency of the bioelectrochemical device in water, due to the favorable interaction between the ETG units and water molecules that prevents π-stacking of the ferrocene unit on the surface of the CNTs. This system can be applied to biosensing, as exemplified for glucose detection. The well-controlled and well-characterized functionalization of essentially clean SWCNTs enabled us to establish the maximum level of impurity content, below which the f-SWCNT intrinsic electrochemical activity is not jeopardized.

  • 8.
    Allali, Naoual
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Urbanova, Veronika
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Etienne, Mathieu
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Mallet, Martine
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Devaux, Xavier
    Département P2M, Institut Jean Lamour, UMR 7198 CNRS-Université de Lorraine.
    Vigolo, Brigitte
    Département CP2S, Institut Jean Lamour UMR 7198 CNRS-Université de Lorraine.
    Fort, Yves
    Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, UMR 7565 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy.
    Walcarius, Alain
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Noël, Maxime
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    McRae, Edward
    Département CP2S, Institut Jean Lamour UMR 7198 CNRS-Université de Lorraine.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Dossot, Manuel
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Mamane, Victor
    Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, UMR 7565 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy.
    Electrocatalytic effect towards NADH induced by HiPco single-walled carbon nanotubes covalently functionalized by ferrocene derivatives2013In: 2012 MRS Fall Meeting: Symposium YY – Low-Voltage Electron Microscopy and Spectroscopy for Materials Characterization, Cambridge University Press, 2013Conference paper (Refereed)
    Abstract [en]

    The present work reports the covalent functionalization of single-walled carbon nanotubes (SWCNTs) by ferrocene derivatives with polyethyleneglycol linkers. A very clean initial sample was chosen to avoid any residual catalyst and carbon impurities. Functionalized SWCNTs (f-CNTs) are deposited on the surface of a glassy carbon electrode (GCE) and this modified electrode is used for oxidizing the cofactor NADH (dihydronicotinamide adenine dinucleotide) in the presence of diaphorase. A clear electrocatalytic effect is evidenced, which can only be attributed to the f-CNTs.

  • 9.
    Allali, Naoual
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Urbanova, Veronika
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Mamane, Victor
    Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, UMR 7565 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy.
    Etienne, Mathieu
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Mallet, Martine
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Devaux, Xavier
    Institut Jean Lamour, Department P2M, UMR 7198 CNRS–Université de Lorraine, Ecole des Mines, 54042 Nancy.
    Vigolo, Brigitte
    Institut Jean Lamour, Department CP2S, UMR 7198 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy.
    Fort, Yves
    Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, UMR 7565 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy.
    Walcarius, Alain
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Noël, Maxime
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    McRae, Edward
    Institut Jean Lamour, Department CP2S, UMR 7198 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy.
    Dossot, Manuel
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Covalent functionalization of few-wall carbon nanotubes by ferrocene derivatives for bioelectrochemical devices2012In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 249, no 12, p. 2349-2352Article in journal (Refereed)
    Abstract [en]

    The present work reports the covalent functionalization of few-wall CNTs (FWCNTs) by ferrocene derivatives to (i) improve their dispersion efficiency in water and (ii) graft electroactive chemical groups on their side-walls in order to promote electron transfer to biomolecules. The functionalized CNTs (f-CNTs) are used to modify a glassy carbon electrode and this modified electrode is used for oxidizing the cofactor NADH (dihydronicotinamide adenine dinucleotide).

  • 10.
    Allali, Naoual
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Urbanova, Veronika
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Mamane, Victor
    Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, UMR 7565 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy.
    Waldbock, Jeremy
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Etienne, Mathieu
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Mallet, Martine
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Devaux, Xavier
    Département P2M, Institut Jean Lamour, UMR 7198 CNRS-Université de Lorraine.
    Vigolo, Brigitte
    Département CP2S, Institut Jean Lamour UMR 7198 CNRS-Université de Lorraine.
    Fort, Yves
    Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, UMR 7565 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy.
    Walcarius, Alain
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Noël, Maxime
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    McRae, Edward
    Département CP2S, Institut Jean Lamour UMR 7198 CNRS-Université de Lorraine.
    Dossot, Manuel
    Département CP2S, Institut Jean Lamour UMR 7198 CNRS-Université de Lorraine.
    Few-wall carbon nanotubes covalently functionalized by ferrocene groups for bioelectrochemical devices2012In: MRS Online Proceedings Library, Cambridge University Press, 2012Conference paper (Refereed)
    Abstract [en]

    The present work reports the covalent functionalization of few-wall CNTs (FWCNTs) by ferrocene derivatives to i) improve their dispersion efficiency in water and ii) to graft electroactive chemical groups on their side-walls in order to promote electron transfer to biomolecules. The functionalized CNTs (f-CNTs) are used to modify a glassy carbon electrode and this modified electrode is used for oxidizing the cofactor NADH (dihydronicotinamide adenine dinucleotide).

  • 11. Andersson, O.
    et al.
    Soldatov, Alexander
    Sundqvist, B.
    Thermal conductivity of C60 at pressures up to 1 GPa and temperatures in the 50-300 K range1996In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 54, no 5, p. 3093-3100Article in journal (Refereed)
    Abstract [en]

    The thermal conductivity λ of C60 shows anomalies near 260 K and 90 K which are associated with the well-established phase transition and glass transition, respectively. Both transition temperatures increase with pressure, at the rates 120 K GPa-1 and 62 K GPa-1, respectively. With increasing temperature, λ of the simple cubic (sc) phase increased below 170 K (glasslike behavior) but decreased above. The glasslike behavior of λ is probably due to a substantial amount of lattice defects. Possible reasons for the change of sign of dλ/dT near 170 K are discussed. In the face centered cubic (fcc) phase (T≳260 K at atmospheric pressure) λ was almost independent of temperature, a behavior which is far from that of an ordered crystal (λ∝T-1 for T≳Debye temperature). This result can be attributed to the molecular orientational disorder of the fcc phase. The relaxation behavior associated with the glassy state and its unusually strong dependence on thermal history are discussed briefly, and data which support a previously reported relaxation model are presented. At room temperature, the density dependencies of λ, (∂ lnλ/∂ lnρ)T, were 5.5 and 9.5 for the fcc and sc phases, which are values typical for an orientationally disordered phase and a normal crystal phase, respectively.

  • 12. Andersson, O.
    et al.
    Soldatov, Alexander
    Sundqvist, B.
    Thermal conductivity of C60 under high pressure1995In: Science and technology of fullerene materials: symposium held November 28 - December 2, 1994, Boston, Massachusetts, U.S.A / [ed] Patrick Bernier, Pittsburgh, Pa: Materials Research Society, 1995, p. 549-554Conference paper (Refereed)
  • 13. Andersson, O.
    et al.
    Soldatov, Alexander
    Sundqvist, Bertil
    Reorientational relaxation in C60 following a pressure induced change in the pentagon/hexagon equilibrium ratio1995In: Physics Letters A, ISSN 0375-9601, E-ISSN 1873-2429, Vol. 206, no 3-4, p. 260-264Article in journal (Refereed)
    Abstract [en]

    The orientational structure of C60 depends on pressure and temperature. Pressurization below the glass transition temperature Tg can freeze in non-equilibrium orientational structures. The relaxation of such structures on heating through Tg has been studied through thermal conductivity measurements and the effects observed are explained in a simple model.

  • 14. Arvanitidis, J.
    et al.
    Meletov, K. P.
    Kourouklis, G. A.
    Papagelis, K.
    Soldatov, Alexander
    Prassides, K.
    Ves, S.
    High pressure study of the 2D polymeric phase of C60 by means of Raman spectroscopy2001In: High Pressure Research, ISSN 0895-7959, E-ISSN 1477-2299, Vol. 18, no 1-6, p. 145-151Article in journal (Refereed)
    Abstract [en]

    The effect of high hydrostatic pressure, up to 12GPa, on the intramolecular phonon frequencies and the material stability of the two-dimensional tetragonal Cm polymer has been studied by means of Raman spectroscopy in the spectral range of the radial intramolecular modes (200-800cm-1). A number of new Raman modes appear in the spectrum for pressures ≈ 1.4 and ≈ 5.0 GPa. The pressure coefficients for the majority of the phonon modes exhibit changes to lower values at P=4.0 GPa, which may be related to a structural modification of the 2D polymer to a more isotropic phase. The peculiarities observed in the Raman spectra are reversible and the material is stable in the pressure region investigated.

  • 15. Arvanitidis, J.
    et al.
    Meletov, K.P.
    Papagelis, K.
    Soldatov, Alexander
    Prassides, K.
    Kourouklis, G. A.
    Ves, S.
    Comparative Raman study of the 1D and 2D polymeric phases of C60 under pressure1999In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 215, no 1, p. 443-448Article in journal (Refereed)
    Abstract [en]

    The effect of symmetry lowering on the phonon spectra as well as the pressure effects on the vibrational spectrum of polymerized C60 were studied by Raman spectroscopy. Drastic changes related to the splitting of degenerate modes of the C60 molecule were observed together with selected softening of some of them. In spite of many similarities in the Raman spectra of the one- (1D) and two-dimensional (2D) polymeric forms of C60, some salient differences in the peak intensities and the appearance of complementary modes are evident. In the Raman spectrum of the 2D polymer under high pressure, new modes, which may be related to the deformations of molecular cages, appear. The observed pressure effects are reversible and the material remains stable for pressures up to 8.8 GPa.

  • 16. Arvantidis, J.
    et al.
    Meletov, K.P.
    Papagelis, K.
    Ves, S.
    Kourouklis, G. A.
    Soldatov, Alexander
    Prassides, K.
    Raman modes of the two-dimensional tetragonal polymeric phase of C60 under high pressure2001In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 114, no 20, p. 9099-9104Article in journal (Refereed)
    Abstract [en]

    The effect of high hydrostatic pressure, up to 12 GPa, on the phonon spectrum and the material stability of the two-dimensional (2D) tetragonal C60 polymer have been studied by means of Raman spectroscopy in the frequency range 100-2000 cm-1. A number of Raman modes appear in the spectrum for pressures above ~1.4 GPa, whose intensities increase with pressure. The pressure coefficients of the majority of the phonon modes change gradually to lower values for pressures around 4.0 GPa. The deformation of the C60 molecular cage along with the change of the material to a more isotropic state (as far as its elastic properties are concerned) resulting from the application of high pressure may be causing the observed effects in the Raman spectra. These effects are reversible upon pressure release and therefore the material is stable in the pressure region investigated.

  • 17.
    Battie, Yann
    et al.
    LCP-A2MC, Université de Lorraine.
    Dossot, Manuel
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine, LCPME UMR 7564 CNRS-Université de Lorraine.
    Allali, Naoual
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mamane, Victor
    Laboratoire de Synthèse Organométallique et Réactivité, Université Henri Poincaré - Nancy, Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, Nancy Université, SRSMC UMR 7565 CNRS-Université de Lorraine, Faculté des Sciences et Techniques.
    Naciri, Aotmane En
    LCP-A2MC, Université de Lorraine.
    Broch, Laurent
    LCP-A2MC, Université de Lorraine.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mild covalent functionalization of single-walled carbon nanotubes highlighted by spectroscopic ellipsometry2016In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 96, p. 557-564Article in journal (Refereed)
    Abstract [en]

    Single-walled carbon nanotubes (SWCNT) synthesized using the HiPco® process and purified thereafter were submitted to two covalent functionalization processes: i) a mild oxidation in a concentrated HNO3 solution using microwave irradiation and ii) a radical functionalization to graft methoxyphenyl groups. The samples were analyzed by Raman spectroscopy and spectroscopic ellipsometry in the energy window 0.07-4.96 eV. The complex dielectric function was analytically calculated in order to extract the real (εr) and imaginary (εi) parts of this function vs. the incident energy of the light. The ellipsometric data in the infrared part of the spectrum revealed that process i) mainly affected the amorphous carbon deposited on the surface of SWCNTs while process ii) strongly changed the electronic nature of the film due to a charge transfer between methoxyphenyl groups and SWCNTs. These results demonstrate the richness of information that spectroscopic ellipsometry is able to bring about on an entire carbon nanotube ensemble compared to Raman spectroscopy, while not suffering from limitation on their electronic structure and/or aggregate state/presence of surfactants.

  • 18.
    Benavides, Vicente
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Chernogorova, Olga
    A.A. Baikov Institute of Metallurgy and Materials Science (IMET), Moscow, Baikov Institute of Metallurgy and Materials Science (IMET), Russian Academy of Sciences.
    Drozdova, Ekaterina I.
    A.A. Baikov Institute of Metallurgy and Materials Science (IMET), Moscow.
    Ushakova, Iraida N.
    A.A. Baikov Institute of Metallurgy and Materials Science (IMET), Moscow.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Raman and electron microscopy study of C60 collapse/transformation to a nanoclustered graphene-based disordered carbon phase at high pressure/temperature2015In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 252, no 11, p. 2626-2629Article in journal (Refereed)
    Abstract [en]

    Transformation of C60 polymers to a superelastic hard carbon (nanoclustered graphene phase (NGP)) occurring in metal matrix at 5 GPa in a temperature interval of 1000–1100 K was studied by optical, scanning electron microscopy (SEM), and Raman spectroscopy. Raman spectral scan across the sample surface allowed us to identify different stages of the structural transformation. The SEM and Raman spectroscopy data testify for the NGP appearance at the defects concentration sites in the parent fullerite structure. We propose that the buckyballs collapse/formation of the NGP is governed by nucleation and growth (diffusive) mechanism unlike earlier discussed in the literature possibility of the martensitic-type (displacive) character of this transformation.

  • 19.
    Botella, Pablo
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Devaux, Xavier
    Institut Jean Lamour, UMR 7198 CNRS–Université de Lorraine.
    Dossot, Manuel
    LCPME UMR 7564 CNRS-Université de Lorraine.
    Garashchenko, Viktor
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Beltzung, Jean Charles
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Physics Harvard University, Cambridge.
    Ananev, Sergey
    Joint Institute for High Temperatures of RAS.
    Single-Walled Carbon Nanotubes Shock-Compressed to 0.5 Mbar2017In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 254, no 11, article id 1700315Article in journal (Refereed)
    Abstract [en]

    Single-walled carbon nanotubes (SWCNTs) have been dynamically (shock) compressed to 0.5 Mbar, above the limit of their structural integrity. Two distinct types of material are identified by high-resolution transmission electron microscopy (HRTEM) and multi-wavelength Raman spectroscopy in the sample recovered after shock: multi-layer graphene (MLG) and a two-phase material composed of nano-clustered graphene and amorphous carbon whereas no diamond-like carbon or carbon nano-onions are found. Peak decomposition of the Raman spectra was used to estimate the coherent scatterers (clusters) size in MLG at 36 nm from the D- to G-band intensity ratio dependence on the photon excitation energy. Botella et al. (article no. 1700315) propose the peak fitting model for decomposition of the Raman spectra of highly disordered carbon material containing graphene nano-clusters and stress the importance of accounting for heptagonal- and pentagonal-ring defects in graphene layers for the analysis of such spectra. The cover image shows HRTEM images and the correspondent Raman spectra of the two types of material along with peak decomposition of the two-phase material with the peaks assigned to heptagons (a) and pentagons (b). Particulars of the SWCNTs transformation to other structural forms of carbon at high pressure/temperature are discussed

  • 20.
    Botella, Pablo
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Devaux, Xavier
    Institut Jean Lamour, UMR 7198 CNRS–Université de Lorraine.
    Dossot, Manuel
    LCPME UMR 7564 CNRS-Université de Lorraine.
    Garashchenko, Viktor
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Beltzung, Jean Charles
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Physics Harvard University, Cambridge.
    Ananev, Sergey
    Joint Institute for High Temperatures of RAS.
    Single-Walled Carbon Nanotubes Shock-Compressed to 0.5 Mbar2017In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 254, no 11, article id 1770259Article in journal (Refereed)
    Abstract [en]

    Single-walled carbon nanotubes (SWCNTs) have been dynamically (shock) compressed to 0.5 Mbar, above the limit of their structural integrity. Two distinct types of material are identified by high-resolution transmission electron microscopy (HRTEM) and multi-wavelength Raman spectroscopy in the sample recovered after shock: multi-layer graphene (MLG) and a two-phase material composed of nano-clustered graphene and amorphous carbon whereas no diamond-like carbon or carbon nano-onions are found. Peak decomposition of the Raman spectra was used to estimate the coherent scatterers (clusters) size in MLG at 36 nm from the D- to G-band intensity ratio dependence on the photon excitation energy. Botella et al. (article no. 1700315) propose the peak fitting model for decomposition of the Raman spectra of highly disordered carbon material containing graphene nano-clusters and stress the importance of accounting for heptagonal- and pentagonal-ring defects in graphene layers for the analysis of such spectra. The cover image shows HRTEM images and the correspondent Raman spectra of the two types of material along with peak decomposition of the two-phase material with the peaks assigned to heptagons (a) and pentagons (b). Particulars of the SWCNTs transformation to other structural forms of carbon at high pressure/temperature are discussed

  • 21.
    Chernogorova, O.
    et al.
    Baikov Institute of Metallurgy and Materials Science (IMET), Russian Academy of Sciences.
    Drozdova, E.
    Baikov Institute of Metallurgy and Materials Science (IMET), Russian Academy of Sciences.
    Ovchinnikova, I.
    Baikov Institute of Metallurgy and Materials Science (IMET), Russian Academy of Sciences.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ekimov, E.
    Vereshchagin Institute for High Pressure Physics RAS, Troitsk.
    Structure and properties of superelastic hard carbon phase created in fullerene-metal composites by high temperature-high pressure treatment2012In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 111, no 11Article in journal (Refereed)
    Abstract [en]

    Treatment of a fullerene soot extract and metal (Co) powder mixture under pressure of 5 and 8 GPa at 1000 °C leads to the transformation of fullerites into superelastic hard phase (SHP) and to simultaneous sintering of the powder mixture to nonporous composite material reinforced by the SHP particles. The structure of the SHP particles reveals a topological relation to the initial fullerite crystal morphology. Upon indentation, the SHP particles demonstrate an elastic recovery of up to 96. The universal microhardness of the SHP particles HU=26 GPa, and their microhardness HV = 35 GPa. A high ratio between the microhardness and elastic modulus (HV/E = 0.19-0.21) of the SHP particles makes them perspective candidates for design of materials with superior wear resistance and tribological properties.

  • 22.
    Chernogorova, Olga P.
    et al.
    Baikov Institute of Metallurgy and Materials Science RAS, Moscow.
    Drozdova, Ekaterina I.
    Baikov Institute of Metallurgy and Materials Science RAS, Moscow.
    Ushakova, Iraida N.
    Baikov Institute of Metallurgy and Materials Science RAS, Moscow.
    Bulychev, S.I.
    Moscow State Industrial University, Moscow.
    Ekimov, E.A.
    Vereshchagin Institute for High Pressure Physics HPPI RAS, Troitsk, Moscow.
    Benavides, Vicente
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Indentation behaviour of superelastic hard carbon2016In: Philosophical Magazine, ISSN 1478-6435, E-ISSN 1478-6443, Vol. 96, no 32-34, p. 3451-3460Article in journal (Refereed)
    Abstract [en]

    Superelastic hard carbon particles widely varying in structure andproperties have been studied by instrumented microindentationtechnique. The carbon particles up to 200 μm in size were producedby fullerene collapse upon high-pressure high-temperature treatmentof metal–fullerene powder mixture with simultaneous sintering ofmetal matrix composite materials (CM) reinforced by the particles.The structure and properties of the carbon particles were controlledby changing synthesis parameters and the state (composition andstructure) of the parent fullerite crystals. The specific features of theinstrumented indentation behaviour of the particles were studied asa function of their hardness. Mechanical properties of the particlestested at loads of up to 1970 mN exhibit an indentation size effect,which becomes more pronounced with increasing hardness of thecarbon particles. Upon holding at a constant load, the fullerenederivedcarbon particles undergo unrecoverable deformation, and theindentation creep CIT increases with increasing particle hardness. Anincrease in hardness of the reinforcing carbon particles substantiallyimproves the wear resistance of the CM and decreases their frictioncoefficient.

  • 23.
    Chernogorova, Olga
    et al.
    A.A. Baikov Institute of Metallurgy and Materials Science (IMET), Moscow.
    Potapova, Iraida
    A.A. Baikov Institute of Metallurgy and Materials Science (IMET), Moscow.
    Drozdova, Ekaterina
    A.A. Baikov Institute of Metallurgy and Materials Science (IMET), Moscow.
    Sirotinkin, Vladimir
    A.A. Baikov Institute of Metallurgy and Materials Science (IMET), Moscow.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vasiliev, Alexander
    National Research Center, Kurchatov Instiute, Moscow.
    Ekimov, Evgeny
    RAS, Vereshchagin Institute of High Pressure Physics, Troitsk, Moscow.
    Structure and physical properties of nanoclustered graphene synthesized from C-60 fullerene under high pressure and high temperature2014In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 104, no 4, article id 43110Article in journal (Refereed)
    Abstract [en]

    C-60 treatment at 5-8 GPa, similar to 1000 degrees C results in the fullerene cage collapse and transformation to a phase with outstanding mechanical properties. A detailed structural analysis of the phase reveals that it comprised 7-12 layer graphene clusters with lateral dimension of 2-4 nm. Raman spectra of the nanoclustered graphene phase are similar to those of disordered sp(2) carbon structure with an admixture of sp(3)-bonded carbon. The phase is characterized by a high (up to 19 GPa) hardness, relatively low (about 70 GPa) Young modulus and up to 95% elastic recovery, determining excellent wear resistance and good antifriction properties. (C) 2014 AIP Publishing LLC.

  • 24.
    Chijioke, Akobuije D.
    et al.
    Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts.
    Nellis, W. J.
    Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Silvera, Isaac F.
    Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts.
    The ruby pressure standard to 150 GPa2005In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 98, no 11, p. 1-9Article in journal (Refereed)
    Abstract [en]

    A determination of the ruby high-pressure scale is presented using all available appropriate measurements including our own. Calibration data extend to 150 GPa. A careful consideration of shock-wave-reduced isotherms is given, including corrections for material strength. The data are fitted to the calibration equation P=(A/B)[(/0)B–1] (GPa), with A=1876±6.7, B=10.71±0.14, and is the peak wavelength of the ruby R1 line.

  • 25.
    Devaux, Xavier
    et al.
    Institut Jean Lamour, Department P2M, UMR 7198 CNRS–Université de Lorraine, Ecole des Mines, 54042 Nancy.
    Vigolo, Brigitte
    Institut Jean Lamour, CNRS – Nancy Université, Laboratoire de Chimie du Solide Minéral, Nancy Université.
    McRae, Edward
    Institut Jean Lamour, CNRS – Nancy Université, Laboratoire de Chimie du Solide Minéral, Nancy Université.
    Valsaque, Fabrice
    Institut Jean Lamour, Nancy Universite.
    Allali, Naoual
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mamane, Victor
    Laboratoire de Synthèse Organométallique et Réactivité, Université Henri Poincaré - Nancy, Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, Nancy Université.
    Fort, Yves
    Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, UMR 7565 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy, Laboratoire de Synthèse Organométallique et Réactivité, Université Henri Poincaré - Nancy.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Dossot, Manuel
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Tsareva, Svetlana Yu.
    Institut Jean Lamour, Nancy Universite.
    Covalent Functionalization of HiPco Single-Walled Carbon Nanotubes: Differences in the Oxidizing Action of H2SO4 and HNO3 during a Soft Oxidation Process2015In: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 16, no 12, p. 2692-2701Article in journal (Refereed)
    Abstract [en]

    The results of a study on the evolution of HiPco single-walled carbon nanotubes during the oxidizing action of H2SO4 and HNO3 are presented. The process conditions used have been chosen so as to avoid any significant damage to the nanotube structure. The type and level of functionalization, the location of the grafted functions on the surface of the nanotube and the changes in morphological characteristics of the samples were examined by using a wide and complementary range of analytical techniques. We propose an explanation for the differences in the oxidizing action of sulfuric and nitric acids. The combined results allow us to suggest possible reaction mechanisms that occur on the surface of the nanotube.

  • 26. Isakina, A.P.
    et al.
    Lubenets, S.V.
    Natsik, V.D.
    Prokhvatilov, A.I.
    Strzhemechny, M.A.
    Fomenko, L.S.
    Aksenova, N.A.
    Soldatov, Alexander
    Structure and microhardness of low pressure polymerized fullerite C601998In: Low temperature physics (Woodbury, N.Y., Print), ISSN 1063-777X, E-ISSN 1090-6517, Vol. 24, no 12, p. 896-903Article in journal (Refereed)
    Abstract [en]

    We have carried out low-temperature x-ray diffraction studies on C60 fullerite polymerized by low quasi-hydrostatic pressure of 1.1 GPa at T = 563 K. It is established that at room temperature in freshly prepared samples three phases mainly coexist, viz. a compressed cubic phase with the lattice parameter a = 13.94 Å, an orthorhombic O' phase with the lattice parameters a = 9.12 Å, b = 9.82 Å, c = 14.60 Å, and a rhombohedral phase of symmetry R3m with the parameters a = 9.20 Å and c = 24.27 Å. Mechanical grinding or annealing at 573 K entails depolymerization of sintered samples and restoration of the fcc structure of pristine C60. During annealing in air, intercalation of fullerite lattice by oxygen molecules occurs as well as a substantial amount of some new phase is formed, most probably with tetragonal symmetry, the chemical composition and structure of which have not been determined. The microhardness of polymerized C60 is higher than that of single crystal samples roughly four-fold at room temperature and by a factor of 2.6 at liquid nitrogen temperature. Analysis shows that polymerization and grain boundaries give contributions to the microhardness of sintered samples but we did not succeed in separating these two contributions. The temperature dependence of the microhardness of polymerized samples exhibits a jump in the vicinity of 260 K, where pristine C60 fullerite undergoes the fcc-sc phase transition. We think that this jump is due to a partial destruction of the polymerized state under indentor as a result of shear straining in inhomogeneous stress fields. Annealing of polymerized C60 at a temperature of 573 K, which restores the fcc phase, leads to a considerable decrease in microhardness, the hardness "jump" near the fcc-sc transition extends in temperature and shifts to lower temperatures

  • 27.
    Kaplan, Alexander
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Noël, Maxime
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Norman, Peter
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Eriksson, Ingemar
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Powell, John
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Fang, Shaoli
    Baughman, Ray
    Incorporation of CNT-yarns into metals by laser melting of powder2012In: 31st International Congress on Applications of Lasers and Electro-Optics (ICALEO) Proceedings, Laser institute of America , 2012, p. 1239-1246Conference paper (Refereed)
  • 28.
    Landström, Anton
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Concina, Isabella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Thermal Defect Modulation and Functional Performance: A Case Study on ZnO–rGO Nanocomposites2019In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951Article in journal (Refereed)
    Abstract [en]

    Herein, a reduced graphene oxide–zinc oxide (rGO–ZnO) hybrid nanocomposite (1 wt% rGO) is synthesized and heat treated at different temperatures, aimed at modulating the intrinsic bulk/surface defects naturally present in nano‐ZnO. The correlation of both the dispersion of rGO within the metal oxide scaffold and the defects present on the semiconductor crystalline lattice with the photocatalytic performance toward the degradation of a molecular dye in water is investigated and discussed. It is shown that several processes compete to determine the catalytic skill of the nanocomposite, which can be enhanced by a simple thermal treatment at moderate temperatures.

  • 29. Lebedkin, S.
    et al.
    Hull, W.E.
    Soldatov, Alexander
    Renker, B.
    Kappes, M. M.
    Structure and properties of the fullerene dimer C140 produced by pressure treatment of C702000In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 104, no 17, p. 4101-4110Article in journal (Refereed)
    Abstract [en]

    A [2+2] cycloaddition cap-to-cap C70 dimer with C2h molecular symmetry was synthesized in high yield by pressure treatment of polycrystalline C70 at 1 GPa and 200° C. It was separated from unreacted monomers by chromatography and characterized by 13C NMR, Raman, and infrared spectroscopy, and other methods. Remarkably, only one isomer was produced out of the five possible [2+2] cycloaddition products which have equally low formation energies according to semiempirical modeling calculations. The dimer obtained is the one favored when C70 molecules adopt an ordered packing with parallel D5 axes. The intercage bonding in C140, its thermal stability, and intercage vibrational modes are similar to those found for the C60 dimer, C120. Both dimers photodissociate to the monomers in solution, probably via excited triplet states. The UV absorption and fluorescence properties of C140 are not very different from those of C70, suggesting only weak electronic interactions between the two cages of C140. In comparison, the pressure-induced dimerization of C60, under the conditions used for C70, results mainly in C60 oligomers and polymeric chains, but the dimer C120 could be isolated at low yield when short reaction times (≤5 min) were used.

  • 30.
    Lebedkin, S.
    et al.
    Forschungszentrum Karlsruhe.
    Hull, W.E.
    Central Spectroscopy Department, German Cancer Research Center, Heidelberg.
    Soldatov, Alexander
    Renker, B.
    Forschungszentrum Karlsruhe.
    Kappes, M.M.
    Forschungszentrum Karlsruhe.
    Dimerization of C70 under high pressure: thermal dissociation and photophysical properties of the dimer C1402000In: Electronic properties od novel materials-molecular nanostructures: XIV International Winterschool/Euroconference / [ed] Hans Kuzmany, Meville, NY: American Institute of Physics (AIP), 2000, p. 77-80Conference paper (Refereed)
    Abstract [en]

    We have recently shown that solid C70 efficiently converts into a cap-to-cap dimer C2hC140 at pressure of ~1 GPa and temperature of ~200 °C [1]. Here we report on measurements of the thermal dissociation of C140 (purified by chromatography) at ambient pressure and its photophysical properties, in particular photogeneration of singlet oxygen (1O2). The kinetics of dissociation of C140 in the solid state between 130 and 200 °C is well described by a simple first-order process, with an activation energy of 1.6±0.03 eV (compare to 1.75±0.05 eV for the C60 dimer C120 [2]). In contrast, the thermal dissociation of C140 dissolved in o-dichlorobenzene shows different, non-Arrhenius behavior, suggesting a strong influence of the molecular surroundings. The quantum efficiency of 1O2 generation in solutions of C140 and C120 is close to unity, i.e. similar to that of C70 and C60.

  • 31.
    Liu, Jie
    et al.
    Laboratoire de Chimie du Solide Minéral, Université Henri Poincaré –Nancy 1.
    Dossot, Manuel
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Olevik, David
    Mamane, Victor
    Laboratoire de Synthèse Organométallique et Réactivité, Université Henri Poincaré - Nancy.
    Vigolo, Brigitte
    Laboratoire de Chimie du Solide Minéral, Université Henri Poincaré –Nancy 1.
    Abrahamsson, David
    Luleå tekniska universitet.
    Jonsson, Henrik
    Luleå tekniska universitet.
    Fort, Yves
    Laboratoire de Synthèse Organométallique et Réactivité, Université Henri Poincaré - Nancy.
    Humbert, Bernard
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    McRae, Edward
    Laboratoire de Chimie du Solide Minéral, Université Henri Poincaré –Nancy 1.
    Preferential functionalisation of carbon nanotubes probed by Raman spectroscopy2008In: Physica. E, Low-Dimensional systems and nanostructures, ISSN 1386-9477, E-ISSN 1873-1759, Vol. 40, no 7, p. 2343-2346Article in journal (Refereed)
    Abstract [en]

    We have chemically grafted methoxypheny functions on HiPco single-walled carbon nanotubes through a radical procedure. To characterise the efficiency of this functionalisation, the materials have been examined via Raman spectroscopy at five laser excitation energies (1.96, 2.33, 2.41, 2.54 and 2.71 eV). This work concentrates mostly on the radial breathing mode band between 150 and 300 cm1. Clear evidence is put forward showing that those tubes which are preferentially functionalised are the smaller-diameter semiconducting tubes and the metallic tubes.

  • 32. Lundin, A.
    et al.
    Soldatov, Alexander
    Sundqvist, B.
    Compressibility and structure of C701995In: Europhysics letters, ISSN 0295-5075, E-ISSN 1286-4854, Vol. 30, no 8, p. 469-474Article in journal (Refereed)
  • 33. Lundin, A.
    et al.
    Soldatov, Alexander
    Sundqvist, B.
    Thermophysical properties of C70 up to 1.2 GPa1995In: Science and technology of fullerene materials: symposium held November 28 - December 2, 1994, Boston, Massachusetts, U.S.A / [ed] Patrick Bernier, Pittsburgh, Pa: Materials Research Society, 1995, p. 555-560Conference paper (Refereed)
  • 34. Lundin, A.
    et al.
    Soldatov, Alexander
    Sundqvist, B.
    Strongin, R.M.
    Bard, L.
    Fischer, J.E.
    Smith, A.B.
    Compressibility of C61D2 up to 1 GPa in the temperature range 175-345 K1996In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 34, no 9, p. 1119-1121Article in journal (Refereed)
    Abstract [en]

    We have measured the bulk modulus K for C61D2 up to 1 GPa in the temperature range 175-343 K. For face-centered cubic C61D2 above 290 K, we find an anomalously low value for K below about 0.15 GPa, possibly indicating pressure-induced changes in the structure. The (extrapolated) zero-p bulk modulus K(0) decreases with increasing T from 6.7 GPa at 175 K to 5.2 GPa at 343 K. A comparison with hypothetical expanded f.c.c. C60 with the same lattice constant shows that K(0) values are similar, indicating that the main intermolecular interactions are still between molecular bellies, not the sidegroups.

  • 35. Lundin, A.
    et al.
    Soldatov, Alexander
    Sundqvist, Bertil
    Compression properties and p-T phase diagrams of C60, C70, and C61D21996In: Proceedings of the Symposium on Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials: [Based on papers presented at the third symposium of the Fullerenes Group of the Electrochemical Society, held at the 189th Meeting of the Electrochemical Society in Los Angeles, California, May 5-10, 1996. This symposium, entitled Fullerenes: Chemistry, Physics and New Directions VIII ...] / [ed] Karl M. Kadish; Rodney S. Ruoff, Pennington, NJ: Electrochemical Society, Incorporated , 1996, p. 1138-1142Conference paper (Refereed)
  • 36.
    Mases, Mattias
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Milyavskiy, Vladimir V.
    Joint Institute for High Temperatures of RAS, Moscow.
    Waldbock, Jeremy
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Dossot, Manuel
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    Devaux, Xavier
    Institut Jean Lamour, Department P2M, UMR 7198 CNRS–Université de Lorraine, Ecole des Mines, 54042 Nancy.
    MacRae, Edward
    Institut Jean Lamour, Department CP2S, UMR 7198, CNRS–Université de Lorraine.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    The effect of shock wave compression on double wall carbon nanotubes2012In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 249, no 12, p. 2378-2381Article in journal (Refereed)
    Abstract [en]

    Double wall carbon nanotubes (DWCNTs) have proven to have a very good structural stability when exposed to high static pressures. We report here on the study of DWCNTs after application of shock wave (dynamic) compression up to 36 GPa in a recovery assembly. TEM images of so-treated samples reveal a threshold between 19 and 26 GPa of shock wave compression above which significant structural damage is induced whereas only minor damage can be detected below. The threshold detected with TEM coincides well with the collapse pressure of DWCNTs previously reported [You et al., High Press. Res. 31, 186 (2011); Aguiar et al., Phys. Chem. C 115, 5378 (2011)]. Raman data demonstrate a gradual accumulation of structural defects via an increase in D-band to G-band intensity ratio (ID/IG-ratio) from ∼0.2 to ∼0.8 in going from the source CNT material to the nanotubes after compression to 36 GPa. Despite severe damage; the DWCNTs exposed to 36 GPa of shock wave compression survived which is evidenced by Raman spectra. The DWCNTs demonstrate a higher susceptibility to structural damage under dynamic than static pressure.

  • 37.
    Mases, Mattias
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Milyavskiy, V.V.
    Waldbock, J.
    Dossot, M.
    Devaux, X.
    McRae, E.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Comparative study of double walled carbon nanotubes exposed to shock wave (dynamic) vs static compression2013In: Book of Abstracts, 7th EEIGM International Conference on Advanced Materials Research: March 21 - 22, 2013, LTU, Luleå - SWEDEN, 2013, p. 3-Conference paper (Refereed)
    Abstract [en]

    We present the study of double walled carbon nanotubes (DWNTs) after application of shock wave (dynamic) compression in a recovery assembly. In the different shock wave experiments the pressure was ramped to a certain level (14, 19, 26 and 36 GPa) with a new CNT sample but always from the same source batch. The recovered samples were characterized by Raman, XPS and HRTEM revealing outer wall disruption along with unzipping and shortening of the CNTs. The carbon nanotube destruction due to temperature increase is minor compared to the effect of the shock wave for the short exposure times in the experiment. Structural damage of the CNTs increases with the shock pressure. Simultaneously, the Raman data exhibit a gradual increase of D/G-band intensity ratio. On the contrary, recent experiments in a diamond anvil cell (DAC) demonstrate high structural stability of DWCNTs exposed to a static pressure of 35 GPa. The ID/IG-ratio after exposure to static pressure starts to increase only after a clear threshold corresponding to the tubes collapse pressure. Remarkably, there are indications that the largest diameter CNTs were destroyed (RBM signal disappeared) by application of the highest shock contrary to the behavior of DWNTs at comparable static pressures. Along with the nature of the applied pressure, we discuss other possible reasons which may have caused such an effect.

  • 38.
    Mases, Mattias
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Noël, Maxime
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Dossot, Manuel
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université.
    McRae, Edward
    Institut Jean Lamour, CNRS – Nancy Université.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Laser-induced damage and destruction of HiPCO nanotubes in different gas environments2011In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 248, no 11, p. 2540-2543Article in journal (Refereed)
    Abstract [en]

    We have studied the thermal and chemical stability of HiPCO-produced single-walled carbon nanotube bundles to high laser power in air and argon. The samples were exposed to 110 kW/cm2 during 8 h with a 1.96 eV laser and the temperature was monitored via downshift of G+-Raman peak. The structural changes in the carbon nanotubes (CNTs) caused by laser heating were monitored by recording their Raman spectra at ambient T (reference conditions) to ensure unaltered resonance conditions. The initial temperature was estimated to be 550 °C and 870 °C in air and argon, respectively. The Raman signal intensity from the CNTs radial breathing mode (RBM) increased rapidly at the beginning of the laser heating both under air and argon due to desorption of impurities for all but the smallest diameter CNTs. The temperature dropped by 30% under argon and 60% under air due to destruction of the absorbers – CNTs in resonance with incident radiation. The final RBM spectra exhibited intensity loss only for the smallest diameter CNTs in argon atmosphere and for all but the largest diameter CNTs in air. Our results demonstrate the importance of (i) impurity desorption from exterior and interior of CNTs; (ii) different temperature thresholds for the CNT destruction due to oxidation and overheating; (iii) the role of photon absorbers on the thermal stability of the sample. The small diameter CNTs are more easily destroyed than large diameter ones. The metallic nanotubes also tend to have lower thermal stability.

  • 39.
    Mases, Mattias
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Noël, Maxime
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mercier, G.
    Institut Jean Lamour, CNRS – Nancy Université.
    Dossot, M.
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université.
    Vigolo, B.
    Institut Jean Lamour, CNRS – Nancy Université.
    Mamane, V.
    Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, Nancy Université.
    Fort, Y.
    Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes, Nancy Université.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    McRae, Edward
    Institut Jean Lamour, CNRS – Nancy Université.
    Effects on Raman spectra of functionalisation of single walled carbon nanotubes by nitric acid2011In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 248, no 11, p. 2552-2555Article in journal (Refereed)
    Abstract [en]

    In the ultimate aim of grafting a fluorescent group on carbon nanotubes (CNTs) using COOH functions as anchoring groups, it was realised that optimisation of the carboxylation step of the CNTs was essential in the overall process. To reach this goal, three different treatment times with refluxed nitric acid have been tested: 2, 5 and 10 h. Electron microscopy has allowed evaluating the microstructure changes and the chemical composition on a local level. Raman spectroscopy has revealed a number of interesting evolutions especially in the D and G bands spectral region. It seems that residual nitric acid molecules may partially transfer charge to CNTs, giving rise to a doping effect, as is well known in graphite intercalation compounds

  • 40. Mases, Mattias
    et al.
    You, Shujie
    Weir, Samuel T.
    Lawrence Livermore National Laboratory.
    Evans, William J.
    Lawrence Livermore National Laboratory.
    Volkova, Yana
    Ural State University.
    Tebenkov, Alexander
    Ural State University.
    Babushkin, Alexey N.
    Ural State University.
    Vohra, Yogesh K.
    University of Alabama at Birmingham.
    Samudrala, G.
    University of Alabama at Birmingham.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    In situ electrical conductivity and Raman study of C60 tetragonal polymerat high pressures up to 30 GPa2010In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 274, no 11/12, p. 3068-3071Article in journal (Refereed)
    Abstract [en]

    Theory predicts that tetragonal polymeric C60 will undergo a phase transition into a metallic phase at pressures around 20 GPa. Raman and structural experiments at high pressures confirmed formation of a new phase above 20 GPa although the question about its electrical properties was still open. We report on the first simultaneous in situ study of vibrational and electrical properties of two-dimensional (2D) tetragonal C60 polymer at pressures up to 30 GPa in a diamond anvil cell (DAC) specially designed for this purpose. Our results reveal an anomaly in Raman spectra and a drop in electrical resistance of the sample at 20-25 GPa. We tentatively associate this anomalous behaviour with a phase transition into the conductive phase although its metallic character is yet to be proven.At high pressures the Raman spectra exhibit a high degree of disorder. Upon pressure release the order was partially restored and, more importantly, a significant amount of the initial 2D polymeric phase was recovered.

  • 41.
    Meletov, K. P.
    et al.
    Physics Division, School of Technology, Aristotle University of Thessaloniki.
    Arvantidis, J.
    Physics Division, School of Technology, Aristotle University of Thessaloniki.
    Tsilika, E.
    Physics Division, School of Technology, Aristotle University of Thessaloniki.
    Assimopoulus, S.
    Physics Division, School of Technology, Aristotle University of Thessaloniki.
    Kourouklis, G.A.
    Physics Division, School of Technology, Aristotle University of Thessaloniki.
    Ves, S.
    Physics Department, Aristotle University of Thessaloniki.
    Soldatov, Alexander
    Prassides, K.
    School of Chemistry, Physics and Environmental Science, University of Sussex, Brighton.
    New pressure-induced phase in tetragonal two-dimensional polymeric C602001In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 63, no 5, p. 54106-Article in journal (Refereed)
    Abstract [en]

    The behavior of the phonon modes of the tetragonal phase of the two-dimensional polymerized C60 has been studied as a function of pressure, up to 27.5 GPa, at room temperature by means of Raman spectroscopy. Gradual transformation of the material to a new phase was observed in the pressure region 19.0–21.0 GPa. As a result of this phase transformation dramatic changes in the Raman spectrum have been recorded. Namely, the total number of bands was reduced and a number of very strong peaks appeared. The Raman spectrum characteristics provide strong indication that the fullerene molecular cage is retained and therefore the high-pressure phase may be related to a three-dimensionally polymerized C60 phase. The high-pressure phase remains stable upon pressure decrease from 27.5 down to 9 GPa. Further release of pressure leads to the destruction of this high-pressure phase to a highly disordered structure whose broad features in the Raman spectrum resemble those of amorphous carbon.

  • 42.
    Müller, Andreas
    et al.
    Luleå tekniska universitet.
    Vigolo, Brigitte
    Institut Jean Lamour, CNRS – Nancy Université.
    McRae, Edward
    Institut Jean Lamour, CNRS – Nancy Université.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Raman study of inhomogeneities in carbon nanotube distribution in CNT-PMMA composites2010In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 247, no 11-12, p. 2810-2813Article in journal (Refereed)
    Abstract [en]

    This work is aimed at characterization of the carbon nanotube (CNT) distribution in polymethyl methacrylate (PMMA)-CNT composites by high-resolution Raman spectroscopy. In particular, we focus on study of the boundary regions between the CNT aggregates and the surrounding areas where the CNTs are well dispersed in the PMMA matrix. Different laser excitation energies (1.96 and 2.33 eV) were used to preferentially probe metallic and semiconducting SWCNTs, respectively. At both photon energies, spectral line scans across the boundary regions were performed revealing a substantial drop in intensity of G+ CNT Raman mode and an increase of the D/G+-intensity ratio. The latter testifies to a preferential dispersion of functionalized CNTs in the PMMA matrix. Certain inhomogeneities were observed by Raman spectral imaging even in the areas with well-dispersed CNTs.

  • 43. Nagel, P.
    et al.
    Pasler, V.
    Lebedkin, S.
    Soldatov, Alexander
    Meingast, C.
    Sundqvist, B.
    Persson, P-A
    Tanaka, T.
    Komatsu, K.
    Buga, S.
    Inaba, A.
    C60 one- and two-dimensional polymers, dimers, and hard fullerite: thermal expansion, anharmonicity and kinetics of depolymerization1999In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 60, no 24, p. 16920-16927Article in journal (Refereed)
    Abstract [en]

    We report on high-resolution thermal expansion measurements of high-temperature-pressure treated C60 [one-dimensional (1D) and (2D) polymers and "hard fullerite"], as well as of C60 dimers and single crystal monomer C60 between 10 and 500 K. Polymerization drastically reduces the thermal expansivity from the values of monomeric C60 due to the stronger and less anharmonic covalent bonds between molecules. The expansivity of the "hard" material approaches that of diamond. The large and irreversible volume change upon depolymerization between 400 and 500 K makes it possible to study the kinetics of depolymerization, which is described excellently by a simple activated process, with activation energies of 1.9±0.1 eV (1D and 2D polymers) and 1.75±0.05 eV (dimer). Although the activation energies are very similar for the different polymers, the depolymerization rates differ by up to four orders of magnitude at a given temperature, being fastest for the dimers. Preliminary kinetic data of C70 polymers are presented as well.

  • 44.
    Noël, Maxime
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ananev, Sergey
    Joint Institute for High Temperatures of RAS, Moscow.
    Mases, Mattias
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Devaux, Xavier
    Institut Jean Lamour, Department P2M, UMR 7198 CNRS–Université de Lorraine, Ecole des Mines, 54042 Nancy.
    Lee, Juhan
    Luleå tekniska universitet.
    Evdokimov, Ivan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Dossot, Manuel
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS–University of Lorraine.
    McRae, Edward
    Institut Jean Lamour, Department CP2S, UMR 7198 CNRS–Université de Lorraine, 54506 Vandoeuvre-les-Nancy, Laboratoire de Chimie du Solide Minéral, Université Henri Poincaré –Nancy 1, Nancy Université, Institut Jean Lamour, CNRS – Nancy Université, Laboratoire de Chimie du Solide Minéral, Nancy Université.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Probing structural integrity of single walled carbon nanotubes by dynamic and static compression2014In: Physica Status Solidi. Rapid Research Letters, ISSN 1862-6254, E-ISSN 1862-6270, Vol. 8, no 11, p. 935-938, article id 4Article in journal (Refereed)
    Abstract [en]

    We report on a first study of single walled carbon nanotubes (SWCNTs) after application of dynamic (shock) compression. The experiments were conducted at 19 GPa and 36 GPa in a recovery assembly. For comparison, an experiment at a static pressure of 36 GPa was performed on the material from the same batch in a diamond anvil cell (DAC). After the high pressure treatment the samples were characterized by Raman spectroscopy and transmission electron microscopy (TEM). After exposure to 19 GPa of shock compression the CNT material exhibited substantial structural damage such as CNT wall disruption, opening of the tube along its axis (“unzipping”) and tube shortening (“cutting”). Dynamic compression to 36 GPa resulted in essentially complete CNT destruction whereas at least a fraction of the nanotubes was recovered after 36 GPa of static compression though severely damaged. The results of these shock wave experiments underline the prospect of using SWCNTs as reinforcing units in material

  • 45.
    Noël, Maxime
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mases, Mattias
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Single walled carbon nanotubes at ultra-high pressure/stress2013In: Bulletin of the American Physical Society, 2013, Vol. 58Conference paper (Refereed)
    Abstract [en]

    We report on the first study of single walled nanotubes (SWCNTs) synthesized by HiPCO method under pressure/stress up to 70 GPa aimed at probing structural stability of small diameter SWCNTs and synthesis of new nanostructured carbon phases. Firstly, the material has been exposed to 25 GPa. Raman spectra of the recovered of material exhibited extremely high defect density and evident recovery of the radial breathing mode (RBM) band with some intensity profile alteration. Secondly, the material was pressurized subsequently to 70 GPa followed by a relatively fast pressure release. Raman characterization provides indications of a transformation of the material to a new structural state as the result of the second pressure cycle. We discuss the structural evolution of the system en-route the final structure which is presumably comprised of deformed graphene nanoribbons and/or polymerized CNTs in addition to the smallest diameter SWCNTs which survived ultra-high pressure/stress.

  • 46.
    Noël, Maxime
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Volkova, Y.
    Ural Federal University, Yekaterinburg.
    Mases, Mattias
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Zelenovskiy, P.
    Ural Federal University, Yekaterinburg.
    Babushkin, A.
    Ural Federal University, Yekaterinburg.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Effects of non-hydrostatic pressure on electrical resistance of bundled single-wall carbon nanotubes2013In: 7th EEIGM International Conference on Advanced Materials Research: 21–22 March 2013, LTU, Luleå, Sweden, IOP Publishing Ltd , 2013, article id 12013Conference paper (Refereed)
    Abstract [en]

    Recent studies have shown that single wall carbon nanotubes (SWCNT) exhibit a sequence of phase transitions and demonstrate a high structural stability up to 35 GPa of quasi-hydrostatic pressure [1] beyond which an irreversible structural transformation occurs. Here we report on the study of electrical resistance of SWCNTs at pressures up to 34 GPa in the temperature range of 293 – 395 K. In the pressure range 10–25 GPathe rate of resistance change decreases considerably. We associate such behavior of the resistance with a structural modification of the SWCNTs or/and change of the conductivity character at high pressure. Raman spectra of the samples recovered after 30 GPa exhibit a large increase of defect concentration in the CNTs. Isobaric temperature dependences of the CNT resistance R(T) measured in the temperature range 300–400 K reveal some changes with pressure whereas the semiconducting character of the R(T) remains unaltered.

  • 47.
    Noël, Maxime
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Volkova, Y.
    Zelenovskiy, P.
    Mases, Mattias
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Babushkin, A.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Electrical transport in bundled single-wall carbon nanotubes under high pressure2013Conference paper (Refereed)
    Abstract [en]

    According to recent experimental data single wall carbon nanotubes (SWCNT) exhibit a sequence of phase transitions and demonstrate a high structural stability up to 35 GPa of non-hydrostatic pressure beyond which an irreversible transformation occurs. Here we report a study of electrical transport in SWCNTs at pressures up to 45 GPa in the temperature range of 300 - 400K. High pressure was generated in diamond anvil cell. The anvils are made of electrically conducting "carbonado"-type synthetic diamond. In the pressure range 10-25 GPa the CNT electrical resistance decreases considerably, whereas above 25 GPa it remains essentially unchanged. Such behaviour of the resistance can be connected to a structural modification of the SWCNTs accompanied by change of the conductivity character at high pressure. Raman spectra of the samples recovered after 30 GPa exhibit a large increase of D/G band intensity ratio. The Radial Breathing Mode part of the spectra remains essentially unaltered which testifies for structural integrity of the nanotubes after exposure to high non-hydrostatic pressure and lack of covalent interlinking between the tubes. Pressure dependences of resistance, activation energy for conductivity and charge carriers mobility were determined and discussed.

  • 48. Olevik, David
    et al.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Dossot, M.
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université.
    Vigolo, B.
    Laboratoire de Chimie du Solide Minéral, Nancy Université.
    Humbert, B.
    Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université.
    McRae, E,
    Laboratoire de Chimie du Solide Minéral, Nancy Université.
    Stability of carbon nanotubes to laser irradiation probed by Raman spectroscopy2008In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 245, no 10, p. 2212-2215Article in journal (Refereed)
    Abstract [en]

    We report on a systematic study of the influence of laser irradiation on the Raman spectra of HiPco-produced single-wall CNTs. Specifically, we have examined the Raman response of bundled CNTs to: i) laser power density; ii) exposure time and iii) photon energy (1.96 and 2.33 eV). Our results show that irreversible destruction of CNTs in the bundles can occur at even low laser power density (0.15 kW/cm2). The tubes with smaller diameters are influenced first and the rate of CNT destruction increases with photon energy. Finally, we determined that when investigating destruction of CNT bundles, the use of a low laser power density is required because changes in the structure of the bundles can lead to sample temperature changes for otherwise identical measurement parameters. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

  • 49. Park, Jiwoong
    et al.
    Pasupathy, Abhay N.
    Goldsmith, Jonas I.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Chang, Connie
    Yaish, Yuval
    Sethna, James P.
    Abruña, Héctor D.
    Ralph, Daniel C.
    McEuen, Paul L.
    Wiring up single molecules2003In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 438-439, p. 457-461Article in journal (Refereed)
    Abstract [en]

    The possibility of using single molecules as active elements of electronic devices offers a variety of scientific and technological opportunities. In this article, we discuss transistors, where electrons flow through discrete quantum states of a single molecule. First, we will describe molecules, where current flows through one cobalt atom surrounded by two insulating terpyridyl ligands. Depending on the length of the insulating part of the molecules, two different behaviors are observed: Coulomb blockade for a longer molecule and the Kondo effect for a shorter molecule. We will also discuss measurements of the C70 fullerene and its dimer (C140). In C140 devices, the transport measurements are affected by an intercage vibrational mode that has an energy of 11 meV. We observe a large current increase when this mode is excited, indicating a strong coupling between the electronic and mechanical degrees of freedom in C140 molecules.

  • 50.
    Pasupathy, A. N.
    et al.
    Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York.
    Park, J.
    Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York.
    Chang, C.
    Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York.
    Soldatov, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Lebedkin, S.
    Institut fur Nanotechnologie, Forschungszentrum Karlsruhe.
    Bialczak, R.C.
    Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York.
    Grose, J.E.
    Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York.
    Donev, L.A.K.
    Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York.
    Sethna, J.P.
    Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York.
    Ralph, D.C.
    Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York.
    McEuen, L.P.
    Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York.
    Vibration-assisted electron tunneling in C140 transistors2005In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 5, no 2, p. 203-207Article in journal (Refereed)
    Abstract [en]

    We measure electron tunneling in transistors made from C140, a molecule with a mass-spring-mass geometry chosen as a model system to study electron-vibration coupling. We observe vibration-assisted tunneling at an energy corresponding to the stretching mode of C140. Molecular modeling provides explanations for why this mode couples more strongly to electron tunneling than to the other internal modes of the molecule. We make comparisons between the observed tunneling rates and those expected from the Franck-Condon model.

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