MAGNETIC FIELD-INDUCED DENSITY WAVE TRANSITION IN A τ-PHASE ORGANIC CONDUCTOR

Abstract

Pulsed magnetic fields to 53 tesla reveal a new high field phase transition in τ-[ P-(S,S) - DMEDT-TTF ]2 ( AuBr 2)( AuBr 2) y (where y ~.75). This transition appears as an abrupt increase in the magnetoresistance at a threshold field ( B Th ~44 tesla for T = 0.55 K). B Th shifts toward higher magnetic fields with increasing temperature, and there is evidence of higher field sub-phases. Measurements of Shubnikov de Haas oscillations below 33 tesla have provided compelling evidence as to the two-dimensional (2D), metallic nature of this compound. In the following report we discuss this new unexpected state, reminiscent of the field-induced spin density wave (FISDW) behavior in the quasi one-dimensional (Q1D) Bechgaard salts.