Angular magnetoresistance oscillations and the shape of the Fermi surface in ?(ET)₂IBr₂

Abstract

Angular magnetoresistance oscillations have been studied systematically for β-(ET)2 IBr2 in the magnetic field rotating in a series of planes perpendicular to the conducting (a, b)-plane. The oscillations have been found in all studied planes. The shape of the Fermi surface transverse cross-section has been reconstructed using the obtained data. Angular dependence of the slow Shubnikov-de Haas oscillations frequency and some fine features of angular magnetoresistance oscillations permit to discuss also the structure of the Fermi surface longitudinal cross-section. The Fermi surface consists most likely of main cylinders with inclined warping planes and small pockets or necks between them.