Structure and magnetic properties of Co₂FeSi film deposited on Si/SiO₂ substrate with Cr buffer layer

Co₂FeSi thin films of 25 nm thickness with 50 nm thick Cr buffer layer was deposited on thermally oxidized Si substrates. Structural and magnetic properties of the films were studied as a function of annealing temperature and substrate temperatures. While the coercivity increases with increase in annealing temperature, it is found to decrease with increase in substrate temperature. A minimum coercivity of 18 Oe has been obtained for the film deposited at 550°C substrate temperature. This was attributed to the formation of L1₂ phase as observed from the GIXRD studies. The films with a good combination of soft magnetic properties and L2₁ crystal structure are suitable for spintronic applications.