LAUSR

Abstract The electronic, magnetic, and mechanical properties of the new equiatomic quarternary Heusler compounds TiZrRuZ (Z = Al, Ga, In) have been studied with the first-principles calculations. Three types of different atomic configurations have been examined and results show the atomic site occupation follows the general site preference rule. The equilibrium lattice constants have been determined and also the total and atom-resolved magnetic moments have been calculated. These new equiatomic quarternary Heusler compounds TiZrRuZ (Z = Al, Ga, In) are ferromagnetic half metals at the ground states. In particular for the total magnetic moment (MT), an integral number of 1 µB is obtained with the main contribution from Ti atoms and it follows the general Slater-Pauling rule, i.e. MT = ZT -18, where ZT is the total valence electron number, 19 for TiZrRuZ. Furthermore, the derived mechanical properties have shown that these materials behave in a strong ductile manner with a high elastic anisotropy, which is further confirmed by the calculated 3D Young's modulus and shear modulus. Their mechanical and dynamic stabilities have also been verified with the generalized elastic criteria and phonon dispersion spectrum. Afterwards, the effects of the uniform and tetragonal strains have been studied. The variation of the conduction band minimum and the valence band maximum with both strains have been revealed and the materials show good robustness of the half metallicity. Also, the total magnetic moment maintains constant of 1 µB against both strains while the atomic magnetic moments vary. In the last, the thermodynamic properties have also been analyzed with the quasi-harmonic Debye model under pressure 0 to 10 GPa and temperature from 0 to 500 K. These materials can be good candidates for the future spintronic application and can even inspire other relative work for material research in this field.