Shubnikov-de Haas (SdH) oscillations are reported for well-characterized (single stage) encapsulated potassium (stages n=4,5,8) and rubidium (n=2,3,5,8) graphite intercalation compounds. Shapes of the Fermi surface (FS) are deduced from the dependence of the FS cross sections on the angle between the c-axis of the sample and H. The temperature dependence (1.4<T25 K) of the amplitudes of the SdH oscillations has been studied to find cyclotron effective masses for specific FS cross sections. A simple phenomenological energy-band model, based on the bands of pristine graphite and c-axis zone folding, is used to calculate SdH frequencies as a function of Fermi energy and is applied to interpret the stage- and intercalant-dependent experimental SdH frequencies and effective masses. The good agreement between the observed and predicted effective masses and the FS cross sections confirms the general validity of this model.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics