Robust half-metallicity in CoZrMnZ (Z = P, As and Sb) quaternary Heusler alloys

The spin-polarized full-potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT) and the exchange and correlation potential is treated with the generalized gradient approximation (GGA) and the Coulomb repulsion (GGA + U), as well as the modified Becke-Johnson approach (GGA-mBJ) are investigated on the structural, elastic, electronic and magnetic properties of CoZrMnZ (Z = P, As, Sb) quaternary Heusler alloys. From GGA-mBJ approximation, the spin-polarized electronic density of states calculations showed that CoZrMnZ (Z = P, As and Sb) compounds display a half-metallic behaviour, with the majority spin being metallic and minority spin being semiconducting, with large energy band gaps equal to 1.122, 0.671, and 1.148 eV, respectively. The calculated total magnetic moment is 1 mu B per formula unit for all compound, and follow the Slater-Pauling rule M-t = Z(t) - 24, where Z(t) is the total number of valence electrons. Under hydrostatic and tetragonal strain all compounds exhibit a robust half-metallicity. The calculated elastic constants and phonon dispersions showed that all compounds are mechanically and dynamically stable in Y-type (I) phase. Besides, the cohesive and formation energies calculations showed that the studied compounds can be realized experimentally. Consequently, these compounds could be promising candidates for spintronic applications.