Effect of Fe substitution on the electronic structure, magnetic and thermoelectric properties of Co2FeSi full Heusler alloy: A first principle study

Abstract A large number of Heusler compounds have been discovered and their properties have been investigated both theoretically and experimentally. Among all the discovered Heusler compounds, Co 2 FeSi is focused for spintronic applications due to its high magnetic moment and high Curie temperature. In this aspect, the electronic structure, magnetic and thermoelectric properties of full Heusler alloy Co 2− x Fe 1+ x Si ( x  = 0–1) have been investigated by using first principle, Full Potential Linear Augmented Plane Wave method. The density of states calculation shows half-metallicity at x  = 0 and 0.25 (i.e. Co 2 FeSi and Co 1.75 Fe 1.25 Si). The calculated magnetic moments were compared with experimental values measured at 4 K and also with the magnetic moments calculated by Slater–Pauling rule. The thermoelectric properties of Co 2 FeSi and Fe 2 CoSi were also calculated over a wide range of temperatures and it was found that Fe 2 CoSi shows higher figure of merit than Co 2 FeSi.