Crystal structure and magnetic properties study on ferromagnet Fe2MnSi0.75Al0.25 Heusler alloy.

Full Heusler alloy Fe 2 MnSi 0.75 Al 0.25 has been prepared by the arc melting method with proper stoichiometry followed by nitrogen atmosphere annealing. Structural and magnetic characterizations have been carried out. X-ray diffraction data analysis reveals that this alloy crystallizes to L2 1 structure in Fm 3 ‾ m space group. It exhibits ferromagnetic behavior below Curie temperature. Curie temperature is found to be around 290 K. The Kouvel-Fisher plot and the Arrott plot have been employed to understand the nature of para to ferromagnetic transition. Here values obtained for critical exponents (β = 0.5284 , γ = 1.084 , δ = 3.05336 ) are convergent with the mean-field model. Law of Approach (LA) to saturation magnetization has been employed to obtain the saturation magnetization and it is found to be maximum (2.4317 μ B /f.u.) at 50 K. [ABSTRACT FROM AUTHOR]