Density functional theory investigation on structural, mechanical, electronic and vibrational properties of Heusler alloys AlXIr2 (X = Co, Cr, Cu, Fe and Zn)

Abstract

This study focuses on the detailed investigation of full-Heusler AlXIr2 (X = Co, Cr, Cu, Fe and Zn) alloys. A first -principal plane-wave pseudopotential method based on density functional theory is adopted. The quantum -espresso package combined with the generalized gradient approach is used to reveal the structural, electronic, magnetic, mechanical and lattice dynamic properties of full-Heusler AlXIr2 (X = Co, Cr, Cu, Fe and Zn) alloys. The elastic constants are used to determine elastic stabilities of alloys based on Born criteria. The analysis showed that all alloys are elastically stable. Further detailed analysis has been carried out to reveal mechanical properties. It is found that all alloys are ductile and anisotropic. The electronic band structures are also obtained. All alloys except for AlCrIr2 are found to be metallic. AlCrIr2 has half-metallic nature. In addition, AlCrIr2, AlFeIr2 and AlCoIr2 has shown magnetic properties. The phonon spectra and density of states are investigated to examine dynamical stability. It is seen that all alloys exhibit dynamical stability due to having positive phonon frequencies.