Preparation, structure, and electrical conductivity of vanadium fluoridegraphite intercalation compound

✍ Scribed by Tsuyoshi Nakajima; Takeo Matsui; Muneyuki Motoyama; Yasuo Mizutani

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 615 KB
• Volume: 26
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(88)90106-6

✦ Synopsis

Graphite intercalation compounds (GIC) of vanadium fluoride have been prepared in a fluorine atmosphere. The GICs prepared from highly oriented pyrolytic graphite (HOPG) were stage l-8 compounds with composition, &_B,VF,,,_,,. The apparent size of intercalated VF;(d,) decreased from 5.33 A to 4.15 A along the c axis with increasing x in C,VF,. Various intercalated structures of VF,-between the carbon layers have been proposed for this change in d, values. The compounds with small d, around 4.2 8, show high stability in the air, which is due to the nestling of the VF; anion between the carbon layers. Electron diffraction measurements have indicated that a well-nestled stage 2 GIC has high regularity in orientation of intercalated VFi anions, which make two large unit cells of the hexagonal system (a,:8.868 A) with the different vectors by 214" from that of graphite lattice. The 19F-NMR spectra and X-ray diffraction data in the low temperature region suggest a reversible phase transition. The highest electrical conductivity was 1.97 x 10s S cm-'. which is 12 times that of pristine HOPG.