Half-metallicity and magnetism of GeTe doped with transition metals V, Cr and Mn: a theoretical study from the viewpoint of application in spintronics

摘要

This work presents results for the magnetic properties of the compound GeTedoped with 3d transition metals V, Cr and Mn from the viewpoint of potentialapplication in spintronics. We report a systematic density-functional study ofthe electronic structure, magnetic and cohesive properties of these ternarycompounds in both rock salt and zinc blende structures. In both cases, it isthe Ge sublattice that is doped with the three transition metals. Some of thesecompounds are found to be half-metallic at their optimized cell volumes. Forthese particular cases, we calculate both exchange interactions and the Curietemperatures in order to provide some theoretical guidance to experimentaliststrying to fabricate materials suitable for spintronic devices. Discussionsrelating our results to the existing experimental studies are provided wheneverapplicable and appropriate. Apparent discrepancy between experimentalobservations and our theoretical result for the case of Mn-doping is discussedin detail, pointing out various physical reasons and possible resolutions ofthe apparent discrepancy.