Investigation of half-metallic properties of full-Heusler alloys of O2BaX (X = Na,K, Rb, and Cs)

Calculations were performed based on first principles and density functional theory using the full-potential linearized augmented plane wave (FPLAPW) to investigate the structural, electronic, and magnetic properties of Heusler compounds of O2BaX (X = Na, K, Rb, and Cs). The results showed that the ground state of four compounds was the AlCu2Mn-type structure in the ferromagnetic state. It was predicted that O2BaX (X = Na, K, Rb, and Cs) compounds were ferromagnetic half-metals in both AlCu2Mn-type and CuHg2Ti-type phases. The origin of the half-metallicity was also studied using electronic density of states (DOSs). These alloys were halfmetals in a wide range of lattice constants indicating its resistance against destructive factors of half-metallicity such as temperature and pressure. The total magnetic moments of O2BaX (X = Na, K, Rb, and Cs) compounds were obtained 1 & mu;B per formula unit at the equilibrium lattice parameter, which were in agreement with Slater-Pauling rule Mtot = (12 - Ztot)& mu;B. The observed results confirm the suitability of O2BaX (X = Na, K, Rb, and Cs) compounds in spintronics applications.