Electronic and Magnetic Effects on Cu Doping $Ti_2NiAl$ Heusler Alloy: A First-Principles Study

We investigate the effect of the electronic and magnetic properties on nonmagnetic Cu-3d atoms doping the Heusler alloy $Ti_2Ni_{1-x}Cu_xAl$ $(0 ≤ x ≤ 1)$ using first-principles calculations. The optimized lattice constants are consistent with the Vegard law, and energies of doped systems become more lower as the increase of x concentration. A critical transition diagram from half-metallic to metallic characters is discussed. In addition, the magnetic interactions between p and d states are illustrated. Finally, magnetic moments are given as a function of x value, which implies that the Slater-Pauling rule is obeyed at low Cu content $(x ≤ 0.2)$.