Angular dependence of the high field phase transition in α-(BEDT-TTF)2TlHg(SCN)4

We report results of a systematic study of the anomalous low temperature state (LTS) angular magnetoresistance (MR) in the quasi-two dimensional organic conductor α-(BEDT-TTF)2TlHg(SCN)4 in fields up to 30 tesla. The high field suppression of the LTS is found to be independent of angle, while the MR maximum, Hmax increases with angle in conjuction with the well studied angular dependent magnetoresistance oscillations (ADMRO). The different magnetic breakdown probabilities above and below Hmax are found to be the source of a novel high field change in the ADMRO shape.