First-principles study on stability, electronic and thermodynamic properties of Ti<Subscript>2</Subscript>CoIn and Ti<Subscript>2</Subscript>NiIn

We present a systemical study on the thermodynamic and physical properties of Ti<Subscript>2</Subscript>CoIn and Ti<Subscript>2</Subscript>NiIn by using first-principles calculations. Both alloys are found to be half-metallic ferromagnets with a total spin magnetic moment per formula unit of 2.00 and 3.00μ <Subscript> B </Subscript>. The stability is evaluated from the physical, chemical and mechanical points of view. The Curie temperature is estimated to be 553.16 K for Ti<Subscript>2</Subscript>CoIn and 1008.59 K for Ti<Subscript>2</Subscript>NiIn, which is well-above the room temperature. In addition, the half-metallicity of Ti<Subscript>2</Subscript>CoIn and Ti<Subscript>2</Subscript>NiIn is retained when the lattice constants are changed by −12.58% to 6.76% and −13.08% to 4.36%, respectively. Finally, using a quasiharmonic Debye model which exhibits Ti<Subscript>2</Subscript>CoIn has a higher thermal stability than Ti<Subscript>2</Subscript>CoIn within a limited temperature (0–500 K). Thus, the present calculations show that Ti<Subscript>2</Subscript>CoIn and Ti<Subscript>2</Subscript>NiIn have a great application potential in the spin valve and magnetic tunnel junction. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2013