Electrical transport properties of low-stage AsF5-intercalated graphite

The in-plane resistivity of stage 1 and stage 2 AsF₅-graphite intercalation compounds was measured using a contactless r.f. eddy current technique from 1.6 to 290 K. The magnetoresistance of a stage 1 compound was similarly measured from 4.2 K to 290 K. The low temperature stage 2 resistivity data show a well-defined intermediate T² region in addition to the usual T high temperature region, in qualitative agreement with the Kukkonen theory and indicative of a small, elongated cylindrical Fermi surface. Stage 2 resistivity data also show, for the first time in a graphite-acceptor compound, an apparent low temperature phase transition at 21 K. Magnetoresistance data were used to determine a stage 1 carrier concentration of 9×10²⁰ holes cm^–3. Resistive anomalies were observed at 200 K and 220 K for stage 1 and stage 2 compounds, respectively.