First-Principles Study of Magnetism and Half-Metallic Properties for the Quaternary Heusler Alloys CoMnTiZ (Z = P, As, and Sb)

Abstract

The ab initio calculations based on the density functional theory (DFT) using the self-consistent full-potential linearized augmented plane wave (FPLAPW) method were performed to study the electronic structure and magnetism of CoMnTiZ (Z = P, As, and Sb) quaternary Heusler compounds. The results showed that these compounds in the stable structure of Y I were true half-metallic (HM) ferromagnets. The minority (half-metallic) band gaps were found to be 0.60 (0.27) 0.36 (0.16), and 0.43 (0.10) eV for Z = P, As, and Sb, respectively. The characteristic of energy bands and origin of minority band gaps were also studied. The total magnetic moments of CoMnTiZ (Z = P, As, and Sb) compounds were obtained 1 μ B per formula unit, which were in agreement with Slater–Pauling rule (M tot = Z tot− 24). The CoMnTiZ (Z = P, As, and Sb) compounds maintained the HM character at ranges of 5.43–5.91, 5.44–5.89, and 5.46–6.22A, respectively, which makes them ideal candidates for spintronic applications.