Effect of Cobalt Addition on Magnetism, Half Metallic and Optical Properties of Fe 2 MnAl Heusler Alloy

In this study on Fe _2-x Co _x MnAl Heusler alloys, we analysed several key properties, including the electronic energy band gap, half-metallicity, magnetic moment and spin polarization (SP). These properties were studied to understand the half-metallic stability as the lattice parameter changed. The alloys consistently maintained the total magnetic moments (M _Total ) predicted by the Slater-Pauling rule (SPR), with values of 2.0 μ _B for x = 0.0, 2.5 μ _B for x= 0.5, 3.0 μ _B for x= 1.0, 3.5 μ _B for x=1.5, and 4.0 μ _B for x= 2.0, across a wide range of lattice variations with 100% value of SP and half-metallic ferromagnetic (HMF) behavior within specific lattice ranges for x = 0.5, this behavior was observed between 5.40-5.70 Å, for x = 1.0, it was seen between 5.35-5.55 Å, for x = 1.5, the range was 5.30-5.60 Å, for x = 2.0, it occurred between 5.25-5.55 Å. Their ability to maintain a stable half-metallic character over a broad spectrum of lattice parameters also makes them strong candidates for applications in spintronics based devices. Optical characteristics of the Fe _{2- x} Co _x MnAl ( x =0 to 2) alloys are investigated in terms of optical Reflectivity R(ω), optical conductivity σ(ω), Energy loss L(ω), Absorption coefficient I(ω), real and imaginary parts of the dielectric function (i.e. ε ₁ (ω) and ε ₂ (ω) respectively), refractive index n(ω) and extinction coefficient K(ω) provided these materials for applicable in making solar cells and optical switches.