Effect of local atomic disorder on the half-metallicity of full-Heusler Co ₂ FeSi alloy: a first-principles study

Abstract

This paper investigates the effect of atomic disorder on the electronic structure, magnetism, and half-metallicity of full-Heusler Co 2 FeSi alloy by using the full-potential linearized augmented plane wave method within the generalized gradient approximation (GGA) and GGA+U schemes. It considers three types of atomic disorders in Co 2 FeSi alloy: the Co-Fe, Co-Si, and Fe-Si disorders. Total energy calculations show that of the three types of disorders, the Fe-Si disorder is more likely to occur. It finds that for the Co-Si disorder, additional states appear in the minority band-gap at the E F and the half-metallcity is substantially destroyed, regardless of the disorder level. On the other hand, the Co-Fe and Fe-Si disorders have little effect on the half-metallicity at a low disorder level. When increasing the disorder levels, the half-metallcity is destroyed at about 9 % of the Co-Fe disorder level, while that stays at 25 % of the Fe-Si disorder level.

Half-metallic ferromagnetism of RbSe and CsTe compounds: A density functional theory study

“…Half-metallic properties are present in various perovskite structures [5,6], Heusler compounds [7,8,9,10], diluted magnetic semi-conductors [11] and metallic oxides [12,13]. All these materials contain transition metal atoms.…”

Effect of Fe substitution on the electronic structure, magnetic and thermoelectric properties of Co 2 FeSi full Heusler alloy: A first principle study

“…Nakatani et al [17] found that there is significant change in polarization of Co 2 FeAl x Si (1Àx) due to doping and also the presence of disorder. The electronic structure of Co 2 FeSi with three different types of disorders (Co-Fe, Co-Si and Fe-Si) has been studied by Li et al [18] and it was showed that Fe-Si type disorder is most likely to occur. Theoretical investigation on the B2 type disorder in Co 2 FeSi depicts that the half metallicity can be retained even at its higher level [19].…”

Density functional study of half-metallic property on B2 disordered Co2FeSi

“…On the other hand, at 12.5 % A2 disorder, there was no band gap found in the minority DOS due to changing of crystal field symmetry in these disordered structures. Li et al [17] investigated the electronic structure of Co 2 FeSi with three different types of disorders by swapping of Co-Fe, Co-Si and Fe-Si positions and found that Fe-Si type disorder is most likely to occur. It is thus essential to prepare good quality Heusler alloy thin films to obtain 100 % spin polarization for spintronic applications because the efficiency of the spintronic devices depends on the spin polarization of the material.…”