Structural, Elastic, Electronic, Magnetic and Optical Properties of Spin Gapless Semiconducting Heusler Alloy Ti2FeSb Using First-Principles Calculations

Density functional theory has been used to study the structural, elastic, electronic, magnetic and optical properties of Ti 2 FeSb Heusler alloy using generalised gradient approximation implemented through the WIEN2k code. The cubic structure of Ti 2 FeSb is mechanically stable in the F-43m space group and shows elastic anisotropic properties with ductile nature. Ti 2 FeSb shows spin gapless semiconductor behaviour along with an indirect energy band gap ( E G ) of 0.10 eV along the Г-Χ in majority spin ( γ -spin) band above the Fermi energy level ( E F ) and 0.90 eV in the minority spin ( δ -spin) band at E F . The total magnetic moment is 3 µ B at optimized lattice constant ( a o ) 6.32 Å and follows the Slater–Pauling curve for inverse Heusler alloys. Robustness of this material with respect to change in the value of a o is evident in the constancy of magnetic moment along with retention of the half metallic nature within a lattice variation ±4% from equilibrium value of a o . Reflectivity, optical conductivity, dielectric function, absorption coefficient and energy loss have also been investigated as a function of incident energy for this alloy.