Anomalous electrical transport and magneto-transport properties at room temperature in Fe0.8Mn1.5As

Abstract

For the Fe0.8Mn1.5As compound, an external magnetic field induces a metamagnetic transition from an antiferromagnetic (AF) phase to a ferrimagnetic (FI) phase above Ts = 285 K, stabilizing the latter phase with the larger unit-cell volume. On cooling, the resistivity curve ρ(T) of Fe0.8Mn1.5As shows an upturn near the temperature-induced AF–FI transition temperature Ts. With an increase in the number of warming and cooling cycles, the resistivity ρ(T) shifts to higher resistivity values, and this anomalous shift is ascribed to a pronounced reduction of the mean-free path of electron scattering. At/near room temperature, the resistivity first decreases with increasing external magnetic field until a critical field, and then after a field-independent stage it increases abruptly with a further increase in the field. In the subsequent field-decreasing process, the resistivity increases almost linearly, resulting in a large hysteresis in resistivity of 56.4 µΩ cm at 290 K (or 20.2 µΩ cm at 295 K) at zero field.