HIGH-FIELD MAGNETIZATION PROCESS IN MN1.9CR0.1SB

The compound Mn1.9Cr0.1Sb shows a first-order transition from the ferrimagnetic (FI) to the antiferromagnetic (AF) state at T(t) = 265 K with decreasing temperature. High magnetic fields (up to 60 T) produce AF-FI transitions below T(t). The temperature dependence of the critical field is nonlinear and shows T2 character at low temperatures (T < 150 K), in contrast to the exchange inversion model of Kittel. This behavior is connected with the itinerant magnetism of 3d-electrons of Mn atoms resulting in a large electronic contribution to the change in free energy at the field-induced first-order AF-FI transition. The field-induced phase transition from the AF to the FI state is accompanied by an increase in the electronic specific heat coefficient gamma by 13 mJ K-2 mol-1 as estimated from the magnetization measurements using thermodynamic relation.