First-principles investigation of the L21 and Xa ordering competition in Co2Feal Heusler alloy

Abstract

Co2FeAl Heusler alloy was selected as a target to study L21 and XA ordering of atoms by first-principles calculations using WIEN2k code. It has been observed that Co2FeAl (CFA) Alloy tend to form L21 type structure,which is more energetically favorable and much stable compared to XA type structures. Further, we observed that the total magnetic moment Mt(µB/f.u.) shows a strong dependence on site preferences of Fe in all available Wyckoff sites. However, this compound does not show a half-metallic character in both types of ordered structuresstill, it can be used as the spin-polarized material for spintronics application. Our results are opposite to usual site preference rule and approving the validity of the Slater-Pauling rule.