Magnetic Heusler Compounds

Heusler compounds are a remarkable class of intermetallic materials with 1:1:1 (often called Half-Heusler) or 2:1:1 composition comprising more than 1500 members. New properties and potential fields of applications emerge constantly; the prediction of topological insulators is the most recent example. Surprisingly, the properties of many Heusler compounds can easily be predicted by the valence electron count or within a rigid band approach. The wide range of the multifunctional properties of Heusler compounds is reflected in extraordinary magnetooptical, magnetoelectronic, and magnetocaloric properties. Co₂-Heusler compounds are predicted and proven half-metallic ferromagnets showing Slater-Pauling type behavior. The recently discovered Mn₂-Heusler compounds are another class of half metallic Heusler compounds which even can be designed to be compensated ferrimagnets. Tetragonal Heusler compounds Mn₂YZ as potential materials for STT applications can be easily designed by positioning the Fermi energy at the van Hove singularity in one of the spin channels.