The First Principle Study of the Structural, Electronic, Magnetic and Mechanical Properties of Fe2-xCoxTiSi (x= 0, 0.5, 1, 1.5, 2) Full Heusler Alloy

Investigation of the Structural, Electronic, Magnetic and Mechanical properties of the Fe2-xCoxTiSi (x = 0.0, 0.5, 1.0, 1.5, 2.0) compounds in both the Hg2CuTi and Cu2MnAl-type structures using the first-principles density functional calculations, were studied by the augmented waves method. The exchange and correlation potential is treated by the generalized gradient approximation parameterized by Perdew-Burke-Erzerhof (GGA-PBE) and GGA- PBE+U scheme is used based on Dudarevs approach. The results show that the Cu2MnAl-type structure is energetically more stable than the Hg2CuTi-type structure for the Fe2TiSi and Co2TiSi compounds at the equilibrium volume. The substitution of Co atom in Fe2TiSi for Fe, changes the semiconducting behavior to half metallic behavior in Fe1.5Co0.5TiSi, Fe1.0 Co1.0TiSi, Fe0.5Co1.5TiSi and Co2TiSi. The magnetic properties for this full Heusler alloys upon substitution approach remains largely unexplored. It is worth noting that Fe2TiSi alloy becomes magnetized after the introduction of Co atom. The mechanical properties of bulk modulus, shear modulus, Youngs modulus E, anisotropic ratio, Poissons ratio m and B/G ratio are also investigated to explore the ductile and brittle nature of these compounds.