Half-metallic properties for the Ti2YZ (Y = Fe, Co, Ni, Z = Al, Ga, In) Heusler alloys: A first-principles study

Using the full-potential local orbital minimum-basis method, the Ti2-based full-Heusler alloys are studied. The results show that these compounds exhibit a half-metallic behavior, however, in contrast to the conventional full-Heusler alloys, the full-Heusler alloys show a Slater–Pauling rule Mt = Zt − 18 between the total spin magnetic moment (Mt) and valence electron concentration (Zt) per unit cell. Low formation enthalpy implies these Heusler alloys can be fabricated experimentally. The origin of the gap in these half-metallic alloys are well understood. It is found that the half-metallic properties of Ti2-based compounds are insensitive to the lattice distortion and a fully spin polarization can be obtained within a wide range of lattice parameters. This is favorable in practical application.

► State-of-the-art Ti2-based Heusler alloys are predicted half-metallic materials.
► Calculated total spin magnetic agree with the Slater–Pauling rule: Mt = Zt − 18.
► The bulk modulus at equilibrium state and the range of pressure exhibiting half-metallic properties are listed.
► The influence of sp atom on structural stability and half-metallic properties also is illustrated quite well.