Peculiarity of topological Hall effect in Mn2Sb0.9Bi0.1 ferrimagnet

The substituted Mn2Sb-based ferrimagnetic (FIM) alloys by other elements have attracted much attention recently due to excellent magnetofunctional properties. However, almost all investigations have been concentrated on the first-order phase transition between antiferromagnetic and FIM state. In this work, a large topological Hall effect (THE) associated with the spin reorientation transition is observed in the Mn2Sb0.9Bi0.1 alloy. Strikingly, the sign reversal of topological Hall resistivity (rho(T)(xy)) is found before and after the SRT temperature T-SR similar to 160 K. Above the T-SR, a positive rho(T)(xy) is observed, e.g., similar to 0.52 mu Omega cm at 320 K. By reducing temperature to 275 K, the rho(T)(xy) value decreases to similar to 0.42 mu Omega cm. It is interesting that, however, the negative rho(T)(xy) value is found below the T-SR , e.g., similar to-0.66 mu Omega cm at 175 K. The physical mechanism about this peculiar THE is discussed in Bi-doped Mn2Sb-based alloys. Published under an exclusive license by NP Publishing.