Giant magnetoresistance associated with a first-order transition between two ferrimagnetic states in Mn2−xZnxSb (x < 0.3) compounds

Abstract

A giant magnetoresistance (GMR) is observed in the Mn2−xZnxSb (x < 0.3) system, with the largest MR ratio of −37.6% in a field of 5 T at 120 K for the Mn1.9Zn0.1Sb compound. Different from other Mn2Sb-based compounds, the GMR in Mn2−xZnxSb is closely correlated with a field-induced transition from a weak ferrimagnetic (WFI) state to a ferrimagnetic (FI) state. It is understood that the influences of both super-zone gap and spin-dependent scattering are responsible for GMR in the present system. Magnetic hysteresis and phase coexistence of the WFI and the FI phases suggest that this WFI–FI transition is of first order. The different mechanisms responsible for butterfly loops of magnetization/resistivity curves in different magnetic states are discussed.