Structural, Elastic, Electronic, and Magnetic Properties of the Full-Heusler Compounds Ti2NiX (X= Al, Ga, and In)

We present a quantum-mechanical first-principle calculation of the structural, elastic, electronic, and magnetic properties of the full-Heusler compounds Ti2NiX (X= Al, Ga, and In). The calculation uses the full-potential linearized augmented plane waves plus local orbital method to describe Ti2-based Heusler alloys. The results show that these compounds exhibit half metallic characteristics over a wide range of mesh parameters and obey the Slater–Pauling rule, which states that the total magnetic moment per unit cell Mt = Zt− 18 for half-Heusler compounds XYZ and Mt = Zt− 24 for full-Heusler X2YZ compounds. For these new alloys Ti2NiX (X= Al, Ga, and In), we initially considered the two possible L21 structures AlCu2Mn and CuHg2Ti. However, two subsequent structural studies showed that only the CuHg2Ti-like structure is half metallic. Over a wide range of mesh parameters, the calculations give a total magnetic moment of 3.00 μB. These results suggest that Ti2NiX (X= Al, Ga, and In) are promising materials for spintronic applications.