First-principle study of the electronic, magnetic and structural characteristics of the Mn2CoAs1−xAlx (x = 0,0.25,0.50,0.75) Heusler alloys

Abstract

First-principles density functional theory approach is adopted to determine the electronic, magnetic and structural characteristics of the Mn2CoAs1−xAlx (x = 0,0.25,0.50,0.75) Heusler alloys. The computations are carried out by WIEN2k code based on full-potential linearized augmented plane wave method (FP-LAPW). Moreover, the exchange-correlation energy functional is treated at the level of the generalized gradient approximation (GGA). Analysis of our computed results of the electronic band structure, as well as the density of states of the Mn2CoAs compound, show it a stable and half-metallic material with an energy band gap value of 0.48 eV. The calculated spin gap values are: 0.627 eV, 0.22 eV and 0.188 eV for Mn2CoAs0.75Al0.25, Mn2CoAs0.50Al0.50 and Mn2CoAs0.25Al0.75 respectively. Furthermore, the calculated total magnetic moment of the Mn2CoAs (4 µB) is found to be in agreement with the Slater–Pauling rule. Thus, our calculations show the Mn2CoAs1−xAlx (x = 0, 0.25, 0.50, 0.75) Heusler alloys potential materials for near future applications in spintronic because of their half-metallic ferromagnetism property.