Investigation of structural, electronical, magnetical and mechanical properties of Fe-Ti-Si ternary of heusler alloys using density functional theory

The structural, electronic, magnetic and mechanical properties of half- and full-Heusler alloys, which are composed of Fe-Ti-Si system, were studied using the density functional theory with the generalized gradient approximation by means of MedeA software. It was determined that while half-Heusler alloys show semi-metallic property, full-Heusler alloys show semiconductor property. In addition, while half-Heusler alloys have magnetic properties, full-Heusler alloys have not. The elasticity constants Cij were calculated using stress-strain technique. In terms of elastic constants, while the half-Heusler alloy was determined as mechanically unstable at β-phase, it has had mechanically stable structure at other phases. When the ratio of B/G was evaluated, it was realized that while the half-Heusler type was ductile material, the full-Heusler type was fragile.