Structural, elastic, electronic, magnetic, and half-metallic properties of a novel rare earth-based quaternary Heusler Alloys LaXTiSi (X = Co, Rh, Ir)

The lanthanum-based LaXTiSi ( X = Co, Rh, Ir) quaternary Heusler alloys have been investigated by employing the density functional theory. According to the structural study, the Y -type (III) structure is more stable for all compounds. The elastic study shows that all alloys are intrinsically stable systems. The band structure and the density of state (DOS) calculated by the GGA approach indicate the half-metallic behavior for the LaXTiSi (X = Co, Rh, Ir) compounds with minority spin band gap values 0.78 eV, 0.76 eV, and 0.89 eV respectively. The half-metallic character is confirmed by the total magnetic moment obtained; for all compounds, the total magnetic moment is equal to 2μB which is in accord with the Slater-Pauling rule ( M = Z tot - 18 ) .