Complete spin gapless semiconductivity in equiatomic quarternary Heusler material TiZrMnAl

Abstract A new equiatomic quarternary Heusler compound TiZrMnAl has been theoretically predicted. Two possible structural configurations are considered under the site preference rule and their equilibrium lattices have been derived. Electronic band structures identify TiZrMnAl compound as the spin gapless semiconductors in both two structure types. The total magnetic moments of TiZrMnAl are both equal to zero with the partial moments of Ti and Zr antiparallelly aligned to that of Mn. This integral value of total moment follows the Slater-Pauling rule in the form of Mt = Zt – 18, where Mt represents the total magnetic moment and Zt is the total number of valence electrons. The mechanical and dynamic stabilities of TiZrMnAl have also been validated and strong elastic anisotropy is further revealed with the calculated directional dependent Young’s modulus and shear modulus for both structures. Besides, the effect of random swap disorder between Ti and Zr atoms has been examined and it is found that through the whole swap range, TiZrMnAl maintains its fully compensated spin gapless semiconductivity, which is a very good property for possible applications in spintronic devices. Lastly, the uniform and tetragonal strains have been accessed and their effects on the electronic and magnetic properties have been studied. This systematic study can provide a comprehensive reference for the further development of Ti and Zr based quarternay Heusler compounds and even inspire other relative studies for the exploration of new spin gapless semiconductors.