Magnetic Field Dependent Susceptibility of (TMTSF)2ClO4

Abstract

The magnetic susceptibility (X)-of slowly cooled single crystals of(TMTSF)₂ClO₄ was measured for H/ /c* with fields up to 10 tesla and 1.7K < T < 300K. No anomaly in X is observed at the anion ordering temperature 24K, with x^Pauli constant for 4.2K < T < 30K. Between 4.2K and 2.2K, x^Pauli increases threefold in aggreement with the high field specific heat data signaling a magnetic field induced phase transition. The magnetic field dependence of the X at 4.2 and 2.0K shows the presence of ∼1500 ppm Curie spins. Such localized spins and their associated Schottky anomaly can account for a large part of the 2 tesla specific heat anomaly reported earlier by Brusetti et at.