Role of Magnetic Exchange Interactions in Chiral-Type Hall Effects of Epitaxial MnxPtSn Films

Abstract

Tetragonal Mn-based Heusler compounds feature multiple exchange interactions resulting in exotic topological magnetic textures, such as antiskyrmions that are complimented by the chiral-type Hall effects. This makes the material class particularly interesting for device applications. We report the relation of the magnetic exchange interactions to the thickness and Mn concentration of MnxPtSn thin films, grown by magnetron cosputtering. The competition of the magnetic exchange interactions determines the finite temperature magnetic texture and thereby the chiral-type Hall effects in external magnetic fields. We investigate the magnetic and transport properties as a function of magnetic field and temperature. We focus on the anomalous and chiral-type Hall effects and the behavior of the dc magnetization in relation to chiral spin textures. We further determine the stable crystal phase for a relative Mn concentration between 1.5 and 1.85 in the I4¯ 2d structure. We observe a spin-reorientation transition in all compounds studied, originating from the competition of exchange interactions on different Mn sublattices. We discuss our results in terms of exchange interactions and compare them with theoretical atomistic spin calculations.