Topological Hall effect associated with spin reorientation transition in tetragonal Mn1.9Co0.1Sb ferrimagnet

Abstract

Ferrimagnetic Mn2Sb-based compounds with the tetragonal structure have been of interest due to multiple magneto-functional properties. But very few investigations about the topological transport properties have been reported in these alloys yet, especially those around the spin reorientation transition (SRT). In this work, a large topological Hall resistivity up to 0.42 μΩ cm is observed at 260 K, ~24 K higher than SRT temperature TSR, in tetragonal Mn1.9Co0.1Sb alloy. What’s more, large topological Hall effect occurs in a relatively wide temperature interval of 100 K from 220 to 320 K, which would mainly originate from the formation of noncoplanar magnetic structure due to magnetic domain rotation when the magnetic moment located at Mn sites rotates from the direction paralleling to c axis to (a, b) plane around the SRT with reducing temperature. The microstructure observation bears this out. The present study implies that Mn2Sb-based alloys should be the promising candidates for technological applications in spintronic devices.