Angular dependent magnetoresistance oscillations in SbCl5-intercalated graphite

We have observed angular dependent magnetoresistance oscillations (ADMRO) in the out-of-plane resistivity of low-stage SbCl 5 -intercalated graphite. This new phenomenon is a semi-classical geometric resonance effect inherent in quasi two-dimensional systems whose Fermi surface is weakly corrugated in the k z -direction. Typically, ADMRO is characterized by peak positions that are periodic in tan θ. The peaks in ϱ zz occur when the average of the k z -component of electron group velocity around its extended orbit is zero. Significant deviations from ‘standard’ behaviour are found. The implications for electronic structure are discussed.