Raman light scattering and c-axis resistivity evidence for a pressure-induced stage transformation in PdAl2Cl8 intercalated graphite.
2000 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, Vol. 62, no 20, 13757-13766 p.Article in journal (Refereed) Published
We have examined several samples of first- to third-stage PdAl2Cl8-intercalated graphite under hydrostatic pressures up to 1 GPa. In stage-1 highly oriented pyrolytic graphite–(HOPG) and single-crystal-graphite-based materials, the c-axis resistivity decreases sharply above a few kilobars; pressure release induces a reversible return to the initial value only in the case of the latter sample. Raman spectra taken in situ under pressure on a HOPG-based material show similarly irreversible effects. Analysis of the spectra taken on higher-stage samples leads to the conclusion that hydrostatic pressure beyond a few kilobars increases the density of the intercalate within the graphitic galleries, transforming the initial sample to a higher-stage material. Since there is no loss of intercalate, the overall intercalate-to-host charge transfer remains constant so that the Raman frequency is approximately the same for both first- and second-stage products. This is an unusual situation in which there is thus an apparent lack of Raman signature in spite of the stage change.
Place, publisher, year, edition, pages
American Physical Society , 2000. Vol. 62, no 20, 13757-13766 p.
Graphite intercalation compounds, graphite, HOPG, intercalation, SCG, single crystal, resistance, resistivity, c-axis direction, Raman spectroscopy, high pressure
Condensed Matter Physics
Research subject Physics
IdentifiersURN: urn:nbn:se:umu:diva-22450DOI: 10.1103/PhysRevB.62.13757OAI: oai:DiVA.org:umu-22450DiVA: diva2:216596