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Lindbäck, Ture
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Mouzon, J., Lindbäck, T. & Odén, M. (2008). Influence of agglomeration on the transparency of yttria ceramics (ed.). Paper presented at . Journal of The American Ceramic Society, 91(10), 3380-3387
Öppna denna publikation i ny flik eller fönster >>Influence of agglomeration on the transparency of yttria ceramics
2008 (Engelska)Ingår i: Journal of The American Ceramic Society, ISSN 0002-7820, E-ISSN 1551-2916, Vol. 91, nr 10, s. 3380-3387Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In this work, five yttria powders with slightly different states of agglomeration, inherited from various procedures of dewatering the same precursor, were densified by a combination of vacuum sintering followed by hot isostatic pressing (HIP). In order to relate the densification behavior of each powder to its state of agglomeration, all powders were characterized by tap density measurements, X-ray diffraction, nitrogen adsorption, and laser scattering, while the microstructures of the corresponding densified samples were studied by optical and scanning electron microscopy. The five yttria powders produced sintered samples that differed remarkably from each other in terms of transparency. These discrepancies were related to the degree of fineness in the powders at two different levels. At the level of primary particles, fine and weakly agglomerated powder was very sinterable, causing abnormal grain growth to occur only in the very late stage of sintering. However, the resulting entrapped pores and reduction due to vacuum sintering were responsible for poor optical properties. At the agglomerate level, a bimodal size distribution was identified for all powders. For powders showing severe agglomeration of the primary particles, increasing the relative content of the smaller size population of agglomerates was found to trigger abnormal grain-growth earlier during presintering. This was attributed to the density around large agglomerates exceeding a critical threshold in the green bodies. Finally, transparency was achieved in samples for which presintering was stopped before grain growth became abnormal. This confirmed that the key to successfully obtaining transparency was to keep porosity intergranular, which could be removed subsequently by HIP treatment.

Nationell ämneskategori
Kemiska processer Annan materialteknik
Forskningsämne
Kemisk teknologi; Materialteknik
Identifikatorer
urn:nbn:se:ltu:diva-5626 (URN)10.1111/j.1551-2916.2008.02633.x (DOI)000259972200042 ()2-s2.0-53349153653 (Scopus ID)3c88a810-a5b7-11dd-b524-000ea68e967b (Lokalt ID)3c88a810-a5b7-11dd-b524-000ea68e967b (Arkivnummer)3c88a810-a5b7-11dd-b524-000ea68e967b (OAI)
Anmärkning
Validerad; 2008; 20081029 (bajo)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Kugler, V. M., Söderlind, F., Music, D., Helmersson, U., Andreasson, J. & Lindbäck, T. (2004). Microstructure/dielectric property relationship of low temperature synthesised (Na,K)NbOx thin films (ed.). Paper presented at . Journal of Crystal Growth, 262(1-4), 322-326
Öppna denna publikation i ny flik eller fönster >>Microstructure/dielectric property relationship of low temperature synthesised (Na,K)NbOx thin films
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2004 (Engelska)Ingår i: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 262, nr 1-4, s. 322-326Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Thin films of (Na,K)NbOx (NKN) were grown by reactive RF magnetron sputtering on polycrystalline Pt80Ir20 substrates, at relatively low growth temperatures between 300°C and 450°C. The results show that the electrical performance and the microstructure of the films are a strong function of the substrate temperature. X-ray diffraction of films grown up to 400°C revealed the formation of only one crystalline NKN-phase with a preferred (002)-orientation. However, a mixed orientation together with a secondary, paraelectric potassium niobate phase, were observed for NKN films deposited at 450°C. The differences in the microstructure explains the variations in the dielectric constants and losses: The single phase NKN films displayed a dielectric constant and a dielectric loss of 506 and 0.011, respectively, while the films with mixed phases exhibited values of 475 and 0.022, respectively. The possibility of fabricating NKN films with relatively high dielectric properties at low growth temperatures, as demonstrated here, is of high technological importance

Nationell ämneskategori
Annan materialteknik
Forskningsämne
Materialteknik
Identifikatorer
urn:nbn:se:ltu:diva-12985 (URN)10.1016/j.jcrysgro.2003.10.035 (DOI)000189098700050 ()2-s2.0-0842330006 (Scopus ID)c231e4d0-6f78-11db-962b-000ea68e967b (Lokalt ID)c231e4d0-6f78-11db-962b-000ea68e967b (Arkivnummer)c231e4d0-6f78-11db-962b-000ea68e967b (OAI)
Anmärkning
Validerad; 2004; 20060917 (cira)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Kugler, V. M., Söderlind, F., Music, D., Helmersson, U., Andreasson, J. & Lindbäck, T. (2003). Low temperature growth and characterization of (Na,K)NbOx thin films (ed.). Journal of Crystal Growth, 254(3-4), 400-404
Öppna denna publikation i ny flik eller fönster >>Low temperature growth and characterization of (Na,K)NbOx thin films
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2003 (Engelska)Ingår i: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 254, nr 3-4, s. 400-404Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Thin (Na,K)NbOx perovskite films (NKN) have been deposited on SiO2/Si(0 0 1) substrates at low temperatures, from 350°C to 550°C, by RF magnetron sputtering. The effects of substrate temperature on microstructure, electrical-, and mechanical properties of the NKN films have been studied. X-ray diffraction analysis revealed that films deposited at temperatures in the range of 450-550°C were crystalline, growing as a single phase, with a preferred orientation of (0 0 1). Films deposited at 350°C, were shown to be amorphous. The growth temperature had a strong influence on the electrical properties of the NKN films and the relative dielectric constants of the obtained films were in between 38 and 78. Variations of the mechanical properties of the NKN films were observed for different substrate temperatures: The elastic moduli and the hardness values ranged from 205±26 to 93±29 GPa, and from 12±2 to around 2 GPa, for films deposited at 550°C and 450°C, respectively.

Nationell ämneskategori
Annan materialteknik
Forskningsämne
Materialteknik
Identifikatorer
urn:nbn:se:ltu:diva-13888 (URN)10.1016/S0022-0248(03)01184-9 (DOI)000183468100016 ()2-s2.0-0037809404 (Scopus ID)d3247f60-d509-11de-bae5-000ea68e967b (Lokalt ID)d3247f60-d509-11de-bae5-000ea68e967b (Arkivnummer)d3247f60-d509-11de-bae5-000ea68e967b (OAI)
Anmärkning

Validerad; 2003; 20091119 (andbra)

Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Abadei, S., Gevorgian, S., Cho, C.-R., Grishin, A., Andreasson, J. & Lindbäck, T. (2001). DC field dependent properties of Na0.5K0.5NbO₃/SiO₂/Si structures at millimeter-wave frequencies (ed.). Applied Physics Letters, 78(13), 1900-1902
Öppna denna publikation i ny flik eller fönster >>DC field dependent properties of Na0.5K0.5NbO₃/SiO₂/Si structures at millimeter-wave frequencies
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2001 (Engelska)Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 78, nr 13, s. 1900-1902Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Dielectric properties of laser-ablated 0.5-μm-thick c-axis epitaxial Na0.5K0.5NbO3 films on high-resistivity (7.7 Ω cm) silicon SiO2/Si substrate are studied experimentally at frequencies up to 40 GHz. For measurements, planar 0.5-μm-thick gold electrodes (interdigital and straight slot) are photolithography defined on the top surface of Na0.5K0.5NbO3 films. The slot width between the electrodes is 2 or 4 μm. 13% capacitance change at 40 V dc bias and Q factor more than 15 are observed at 40 GHz, which makes the structure useful for applications in electrically tunable millimeter-wave devices

Nationell ämneskategori
Annan materialteknik
Forskningsämne
Materialteknik
Identifikatorer
urn:nbn:se:ltu:diva-3894 (URN)10.1063/1.1353838 (DOI)000167744000033 ()2-s2.0-0035952785 (Scopus ID)1be01820-6f66-11db-962b-000ea68e967b (Lokalt ID)1be01820-6f66-11db-962b-000ea68e967b (Arkivnummer)1be01820-6f66-11db-962b-000ea68e967b (OAI)
Anmärkning

Validerad; 2001; 20060917 (cira)

Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Cho, C.-R., Grishin, A., Andreasson, J., Lindbäck, T., Abadei, S. & Gevorgian, S. (2000). Ferroelectroc Na0.5K0.5NbO3 films for voltabe tunable microwave devices (ed.). In: (Ed.), Materials Issues for Tunable RF and Microwave Devices II : MRS fall conference: . Paper presented at MRS Fall Conference : 27/11/2000 - 01/12/2000 (pp. 19-24). Materials Research Society
Öppna denna publikation i ny flik eller fönster >>Ferroelectroc Na0.5K0.5NbO3 films for voltabe tunable microwave devices
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2000 (Engelska)Ingår i: Materials Issues for Tunable RF and Microwave Devices II : MRS fall conference, Materials Research Society, 2000, s. 19-24Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Single phase Na0.5K0.5NbO3 (NKN) thin films have been pulsed laser deposited on Al2O3(01-12), LaAlO3(001), and MgO(001) single crystal substrates as well as onto SiO2/Si(001) wafers to demonstrate films feasibility for voltage tunable microwave device applications. NKN film texture has been found to be quite different on three different single crystals: highly c-axis oriented on Al2O3, "cube-on-cube" epitaxial quality on LaAlO3, bi-axial textures on MgO, while NKN films grown on Si substrate with various thickness of SiO2 buffer layer possess highly c-axis oriented quadrupled structure. NKN film interdigital capacitors fabricated onto single crystal oxide substrates showed tunability of 30-40 % and dissipation factor of 0.01-0.02 at 1 MHz and applied electric field of 100kV/cm. Microwave frequency measurements for NKN/Si varactors yield 13 % tunability and dielectric loss tan delta as low as 0.012 at 40 GHz under 200 kV/cm applied bias.

Ort, förlag, år, upplaga, sidor
Materials Research Society, 2000
Serie
MRS proceedings ; 656E
Nationell ämneskategori
Annan materialteknik
Forskningsämne
Materialteknik
Identifikatorer
urn:nbn:se:ltu:diva-40701 (URN)fee1e080-28d3-11de-bce5-000ea68e967b (Lokalt ID)fee1e080-28d3-11de-bce5-000ea68e967b (Arkivnummer)fee1e080-28d3-11de-bce5-000ea68e967b (OAI)
Konferens
MRS Fall Conference : 27/11/2000 - 01/12/2000
Anmärkning

Godkänd; 2000; Bibliografisk uppgift: Titel: Materials Issues for Tunable RF and Microwave Devices II; 20090414 (cira)

Tillgänglig från: 2016-10-03 Skapad: 2016-10-03 Senast uppdaterad: 2017-11-25Bibliografiskt granskad
Cho, O.-R., Khartsev, S., Grishin, A. & Lindbäck, T. (1999). Preparation of Na0.5K0.5NbO3/La0.6Sr 0.2Mni.2O3/LaAIO3 thin film structures by pulsed laser deposition (ed.). In: (Ed.), Marilyn E. Hawley (Ed.), Multicomponent oxide films for electronics: symposium held April 6 - 8, 1999, San Francisco, California, U.S.A ; [contains papers presented at Symposium BB, Multicomponent oxide films for electronics held at the 1999 MRS Spring Meeting]. Paper presented at Symposium BB, Multicomponent oxide films for electronics : 06/04/1999 - 08/04/1999 (pp. 149-154). Warrendale, Pa: Materials Research Society
Öppna denna publikation i ny flik eller fönster >>Preparation of Na0.5K0.5NbO3/La0.6Sr 0.2Mni.2O3/LaAIO3 thin film structures by pulsed laser deposition
1999 (Engelska)Ingår i: Multicomponent oxide films for electronics: symposium held April 6 - 8, 1999, San Francisco, California, U.S.A ; [contains papers presented at Symposium BB, Multicomponent oxide films for electronics held at the 1999 MRS Spring Meeting] / [ed] Marilyn E. Hawley, Warrendale, Pa: Materials Research Society, 1999, s. 149-154Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

We report on ferroelectric/giant magnetoresistive Nao.sKo.sNbCVLao.oSrojMniO} (NKN/LSMO) heterostructures gro\vn onto LaAlOj (001) single crystal using KrF pulsed laser ablation of stoichiometric ceramic target. Main processing parameters have been optimized to obtain smooth LSMO template layer, avoid NKN-LSMO interdiffusion, preserve NKN stoichiometry against the lost of volatile potassium and sodium and achieve reasonable reliability of NKN film performance. X-ray diffraction 0- 20 scans and rocking curves evidence for single-phase content and high c-axis orientation both in template LSMO and top NKN layers. Ferroelectric measurements yield remnant polarization P, of 1.5 (.iC/cm2 and spontaneous polarization Ps of 7 jiC/cm2 at electric field strength of 130 kV/cm. At room temperature, dielectric permittivity e' and dissipation factor tancJhave been found to vary from 595 to 555 and 0.046 to 0.029 respectively in the frequency range of 0.4 to 20 kHz. At 10 kHz dielectric permittivity linearly increases from 410 to 650 in the temperature range 77 K to 415 K while the dissipation factor below 320 K does not exceed 3%

Ort, förlag, år, upplaga, sidor
Warrendale, Pa: Materials Research Society, 1999
Serie
Materials Research Society Symposium Proceedings, ISSN 0272-9172 ; 574
Nationell ämneskategori
Kompositmaterial och -teknik Annan materialteknik
Forskningsämne
Polymera konstruktionsmaterial; Materialteknik
Identifikatorer
urn:nbn:se:ltu:diva-27302 (URN)33750847675 (Scopus ID)0b6df8b0-4063-11de-bc0c-000ea68e967b (Lokalt ID)1558994815 (ISBN)0b6df8b0-4063-11de-bc0c-000ea68e967b (Arkivnummer)0b6df8b0-4063-11de-bc0c-000ea68e967b (OAI)
Konferens
Symposium BB, Multicomponent oxide films for electronics : 06/04/1999 - 08/04/1999
Anmärkning
Godkänd; 1999; 20090514 (ysko)Tillgänglig från: 2016-09-30 Skapad: 2016-09-30 Senast uppdaterad: 2017-11-25Bibliografiskt granskad
Li, W. B., Lei, B., Lindbäck, T. & Warren, R. (1999). Stresses developed in reaction-bonded ceramics (ed.). Paper presented at . Journal of the European Ceramic Society, 19(3), 277-283
Öppna denna publikation i ny flik eller fönster >>Stresses developed in reaction-bonded ceramics
1999 (Engelska)Ingår i: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 19, nr 3, s. 277-283Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

A physical model is presented that predicts the stress distribution created in a particle during its reaction with a surrounding reactant to form a uniform layer of reaction product on its surface, when the reaction involves a volume change. The results of the model are applied specifically to the case of silicon reacting with nitrogen to form Si3N4. The model predicts the generation of a high, tensile hydrostatic stress in the Si core as well as high tensile radial stress and compressive tangential stress in the nitride layer. Although the model is restricted to elastic deformation only and therefore predicts unrealistically high stresses in some cases, the results are anyway of relevance in the consideration of possible non-elastic processes such as creep and fracture and also in assessing the possible effect of stress on the reaction equilibrium. It is predicted that the nitride reaction layer would fracture during the nitridation process. A second model is also presented predicting the residual stresses arising during cooling of a partially reacted particle as a result of the difference in thermal expansion of the reactant core and the reaction product layer. In the case of the reaction of silicon to silicon nitride these thermal expansion mismatch stresses are significant but small compared to the stresses due to the chemical reaction.

Nationell ämneskategori
Annan materialteknik
Forskningsämne
Materialteknik
Identifikatorer
urn:nbn:se:ltu:diva-3641 (URN)10.1016/S0955-2219(98)00271-4 (DOI)000079038900001 ()17542c80-f3ee-11db-ac9f-000ea68e967b (Lokalt ID)17542c80-f3ee-11db-ac9f-000ea68e967b (Arkivnummer)17542c80-f3ee-11db-ac9f-000ea68e967b (OAI)
Anmärkning
Godkänd; 1999; 20070426 (cira)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Babushkin, O., Lindbäck, T., Luc, J.-L. & Lebalis, J.-Y. M. (1998). Reaction sequence in the formation of perovskite Pb(Zro0.48Ti0.52)O3-Pb(Nb2/3Ni1/3)O3 solid solution: Dynamic heat-treatment (ed.). Paper presented at . Journal of the European Ceramic Society, 18(7), 737-744
Öppna denna publikation i ny flik eller fönster >>Reaction sequence in the formation of perovskite Pb(Zro0.48Ti0.52)O3-Pb(Nb2/3Ni1/3)O3 solid solution: Dynamic heat-treatment
1998 (Engelska)Ingår i: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 18, nr 7, s. 737-744Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The sequence of the solid state reactions in the PbOZrO 2-TiO2-Nb2O5-NiO system has been investigated. The oxide mixing route utilised in sample preparation was selected in order to determine the basic reaction path in the formation of the PZTPNN perovskite phase. It has been established that the main intermediate phases formed prior to PZTPNN are PbTiO3 and pyrochlore Pb-Nb-based phases. The sequence in the pyrochlore formation was from tetragonal Pb3Nb2O8 (500 °C) to rhombohedral Pb2Nb2O7 (600-750 °C) and finally to cubic Pb3Nb4O13 (650-850 °C). The formation of the perovskite phase proceeded from mutual solubility of PbTiO3 and pyrochlore Pb3Nb4O13 phases, accompanied by dissolving of residuals (PbZrO3 and NiO) in the perovskite solid solution formed

Nationell ämneskategori
Annan materialteknik
Forskningsämne
Materialteknik
Identifikatorer
urn:nbn:se:ltu:diva-3390 (URN)10.1016/S0955-2219(97)00187-8 (DOI)000074654300001 ()136f5e70-fc84-11db-b816-000ea68e967b (Lokalt ID)136f5e70-fc84-11db-b816-000ea68e967b (Arkivnummer)136f5e70-fc84-11db-b816-000ea68e967b (OAI)
Anmärkning
Godkänd; 1998; 20070507 (cira)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Li, W., Lei, B. & Lindbäck, T. (1997). A kinetic model for reaction bonding process of silicon powder compact (ed.). Paper presented at . Journal of the European Ceramic Society, 17(9), 1119-1129
Öppna denna publikation i ny flik eller fönster >>A kinetic model for reaction bonding process of silicon powder compact
1997 (Engelska)Ingår i: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 17, nr 9, s. 1119-1129Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In order to obtain detailed information about the kinetics and the reaction nature of a complex reaction process like reaction bonding of silicon nitride, mathematical modelling of the process is necessary. The previous quantitative models for this process have been based only on the mechanism that the nitrogen diffuses through the solid silicon nitride without taking into account the multiple reaction mechanisms. In the present study, a comprehensive kinetic model, which is based on analysis of the multiple mechanisms in a silicon powder compact reacting with nitrogen gas and forming silicon nitride, is constructed for a solid-gas reaction bonding process with specific application to the reaction-bonding of silicon nitride. The model will incorporate the rate equation for each mechanism into a constitutive equation from which more complete information of process kinetics can be predicted. The results predicted by the present model have been compared with previous experimental results and satisfactory agreement obtained

Nationell ämneskategori
Annan materialteknik
Forskningsämne
Materialmekanik
Identifikatorer
urn:nbn:se:ltu:diva-6667 (URN)10.1016/S0955-2219(96)00212-9 (DOI)A1997XG51700006 ()4edc37f0-f3ef-11db-ac9f-000ea68e967b (Lokalt ID)4edc37f0-f3ef-11db-ac9f-000ea68e967b (Arkivnummer)4edc37f0-f3ef-11db-ac9f-000ea68e967b (OAI)
Anmärkning
Godkänd; 1997; 20070426 (cira)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Babushkin, O., Lindbäck, T., Brooks, K. & Setter, N. (1997). PZT phase formation monitored by high-temperature X-ray diffractometry (ed.). Paper presented at . Journal of the European Ceramic Society, 17(6), 813-818
Öppna denna publikation i ny flik eller fönster >>PZT phase formation monitored by high-temperature X-ray diffractometry
1997 (Engelska)Ingår i: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 17, nr 6, s. 813-818Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The crystallisation kinetics of amorphous sol-gel PZT thin films were investigated using high-temperature X-ray diffraction. Crystallisation for different isotherms was monitored as a function of time. Phase transformation data were obtained from integrated X-ray peak intensities which were calibrated based on image analysis of the surface microstructure of the samples at the end of the isothermal treatments. An activation energy of 310 kJ/mol was obtained without assuming a specific kinetic model. From the transformation data, a TTT diagram was constructed for the ranges studied.

Nationell ämneskategori
Annan materialteknik
Forskningsämne
Materialteknik
Identifikatorer
urn:nbn:se:ltu:diva-14544 (URN)10.1016/S0955-2219(96)00133-1 (DOI)A1997WQ72500009 ()deaca750-f3ec-11db-ac9f-000ea68e967b (Lokalt ID)deaca750-f3ec-11db-ac9f-000ea68e967b (Arkivnummer)deaca750-f3ec-11db-ac9f-000ea68e967b (OAI)
Anmärkning
Godkänd; 1997; 20070426 (cira)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad

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