DIFFERENT TYPES OF ANGULAR MAGNETORESISTANCE OSCILLATIONS IN THE LOW-TEMPERATURE AND HIGH-TEMPERATURE STATES OF THE ORGANIC CONDUCTOR (BEDT-TTF)2KHG(SCN)4

Angular oscillations of semi-classical magnetoresistance of (BEDT-TTF)2KHg(SCN)4 have been studied at different temperatures under a magnetic field rotated in various planes perpendicular to the highly conducting ac-plane. At temperatures above the phase transition, T > T(p) almost-equal-to 8 K, the oscillations are attributed to the electron motion along the closed orbits of the Fermi surface cylinder. In contrast, the low-temperature oscillations are found to be associated with the existence of a specific plane determined most likely by the wave vector of the superstructure arising below T(p).