Hypervelocity cluster ion impacts on free standing graphene: Experiment, theory, and applicationsShow others and affiliations
2019 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 150, no 16, article id 160901Article in journal (Refereed) Published
Abstract [en]
We present results from experiments and molecular dynamics (MD) simulations obtained with C60 and Au400 impacting on free-standing graphene, graphene oxide (GO), and graphene-supported molecular layers. The experiments were run on custom-built ToF reflectron mass spectrometers with C60 and Au-LMIS sources with acceleration potentials generating 50 keV C2+ 60 and 440–540 keV Au4+ 400. Bombardmentdetection was in the same mode as MD simulation, i.e., a sequence of individual projectile impacts with separate collection/identification of the ejecta from each impact in either the forward (transmission) or backward (reflection) direction. For C60 impacts on single layer graphene, the secondary ion (SI) yields for C2 and C4 emitted in transmission are ∼0.1 (10%). Similar yields were observed for analyte-specific ions from submonolayer deposits of phenylalanine. MD simulations show that graphene acts as a trampoline, i.e., they can be ejected without destruction. Another topic investigated dealt with the chemical composition of free-standing GO. The elemental composition was found to be approximately COH2. We have also studied the impact of Au400 clusters on graphene. Again SI yields were high (e.g., 1.25 C− /impact). 90–100 Au atoms evaporate off the exiting projectile which experiences an energy loss of ∼72 keV. The latter is a summation of energy spent on rupturing the graphene, ejecting carbon atoms and clusters and a dipole projectile/hole interaction. The charge distribution of the exiting projectiles is ∼50% neutrals and ∼25% either negatively or positively charged. We infer that free-standing graphene enables detection of attomole to zeptomole deposits of analyte via cluster-SI mass spectrometry
Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019. Vol. 150, no 16, article id 160901
National Category
Other Physics Topics
Research subject
Applied Physics
Identifiers
URN: urn:nbn:se:ltu:diva-73779DOI: 10.1063/1.5080606ISI: 000466698700001PubMedID: 31042896Scopus ID: 2-s2.0-85064967497OAI: oai:DiVA.org:ltu-73779DiVA, id: diva2:1307750
Note
Validerad;2019;Nivå 2;2019-04-29 (johcin)
2019-04-292019-04-292019-06-24Bibliographically approved