Electronic and Magnetic Properties of Fe2−xCoxTiSi (x = 0, 0.5, 1, 1.5, 2) Heusler Alloys

The first principles calculations are carried out to understand the half metallic and ferromagnetic properties of Fe 2− x Co x TiSi ( x = 0, 0.5, 1, 1.5, 2) full Heusler alloys. The stable structure is predicted as L2 1 structure (Cu 2 MnAl phase). The lattice constant value of Fe 2− x Co x TiSi Heusler compounds increases as the value of x increases. These alloys exhibit half metallic ferromagnetism (except Fe 2 TiSi) with small spin flip gap at the minority spin state. At high pressure, semiconductor to metallic phase transition is observed in Fe 2 TiSi while half metallic to metallic phase transition is observed in Fe 1.5 Co 0.5 TiSi, Fe 1.0 Co 1.0 TiSi, Fe 0.5 Co 1.5 TiSi and Co 2 TiSi. The spin polarization of these compounds (except Fe 2 TiSi) is 100%. Hence, these compounds are suitable for spin injection devices in spintronics.