Structural and Magnetic Study on the Effect of Substitution of Cobalt by d-Valent Elements of Co sub(2) FeSi Heusler Alloy

In this paper, the effect of substitution of Co by d-valent elements such as Ag and Pt on electronic structure and magnetic properties of full Heusler type Co sub(2) FeSi alloys was investigated. Structural study reveals the presence of a small gap in the minority band structure around the vicinity of the Fermi level on Co sub(2) FeSi resulting to half-metallic behaviour. However, CoFeSiAg and CoFeSiPt cannot preserved the half-metalicity due to disappearing of the gap in the minority band structure due to the creation of new states around the Fermi level in the minority density of states. The variation in the magnetic moment of Co sub(2) FeSi with change of the atoms was attributed to the change in the local magnetic moment of atoms.