Magnetic properties of Ti2MnAl, Ti2FeAl and Ti2FeGa compounds

Abstract Here, we investigate particular Heusler compounds which were previously predicted by ab initio calculations to have an interesting electronic structure and possible spin-gapless semiconductor state. We synthesized polycrystalline samples, determined crystal structure using X-ray diffraction and performed magnetization measurements. In addition, we present here density functional theory (DFT) calculations for several variants of the unit cell possible for these compounds, and in particular, for structural variant where disorder between Mn or Fe site and p element is present. We found that Ti2MnAl exhibits nonmagnetic ground state, whereas for the Ti2FeAl and Ti2FeGa ferromagnetic ordering is preferred over the antiferromagnetic one. The ordering temperatures observed for Ti2FeAl and Ti2FeGa are in the 30–50 K range, with the latter showing some spin glass type behaviour.