First-principles study of the physical properties of the new quaternary Heusler alloy CoMnVZ ($Z$ = Sn and Sb)

The physical properties of two new quaternary Heusler alloys CoMnVSn and CoMnVSb were systematically studied by using first-principles calculation. The results show that the type-1 structures of ferromagnetic phase for these two alloys are the most stable. They all exhibit half-metallic behavior at equilibrium, and their half-metallic characteristics are maintained in the lattice region of 5.73–6.19 $\mathring{\mathrm{A}}$ for CoMnVSn and 5.82–6.18 $\mathring{\mathrm{A}}$ for CoMnVSb. The calculated magnetic moment Mt of each molecular unit in the half-metal lattice region strictly follows the Slater–Pauling empirical rule $M_t=Z_t-24$, where $Z_t$ is the number of valence electrons. The elastic constants show that the mechanical properties of the two compounds are stable at equilibrium, and the anisotropy factor and three-dimensional Young’s modulus confirm that they have anisotropy. It is expected that the CoMnVSn and CoMnVSb alloys are promising candidates in spintronics