Magnetotransport investigation of the low-temperature state oftransition(BEDT-TTF)₂TIHg(SCN)₄ : evidence for a Peierls-type transition

Abstract

Detailed magnetoresistance measurements have been performed on (BEDT-TTF)2TlHg(SCN)4. An analysis of angle dependent semi-classical magnetoresistance oscillations is presented in connection with possible changes in the electron spectrum at low temperatures. A spin density wave is proposed to arise leading to a modification of the Fermi surface so that new open sheets appear, consistent with the observed angular magnetoresistance oscillations. Some details of the Shubnikov-de Haas effect are also presented which can be explained by the existence of a magnetic breakdown network, in agreement with the proposed low- temperature electronic state of the compound.