Effect of Ni and Sn doping on the half-metallicity of full Heusler Ti2CoIn alloy

• Both of Ti2CoIn and Ti2NiIn are half-metallic ferromagnets with a total spin magnetic moment of 2.00 and 3.00 μB.
• Ti2Co0.75Ni0.25In0.25Sn0.75 system has the largest spin-flip gap which is up to 0.32 eV.
• The spin magnetic moments of doped systems obey the Slater–Pauling rule.
• There is the largest density of states to 7.30 states/eV for Ti2Co0.75Ni0.25In at the Fermi level.

We investigate the effect of doping and disorder of Ti2Co1−xNixIn1−ySnyTi2Co1−xNixIn1−ySny (x, y=0.0, 0.25, 0.50, 0.75, 1.00) employing the virtual crystal approximation. The results show that all alloys under study are half-metals, and their total spin moments follow the so-called Slater–Pauling behavior of the ideal half-metallic systems. Especially, we concentrate on the properties related to the spin-flip gap and the density of states at the Fermi level, and present the possibility to engineer the properties by changing the relative concentrations of the transition metal and sp atoms in a way of dope or disorder. In realistic applications, the spin-flip gap and the density of states at the Fermi level are needed for large values of the perfectly spin-polarized current in spintronic devices such as spin valves or magnetic tunnel junctions. In the manuscript, the properties with respect to the different transition metal and sp atoms concentrations are provided, which offers a choice to obtain ideal half-metallicity in spintronics device applications.