Ab initio study of the fundamental properties of $\hbox {Zn}_{1-x} \hbox {TM}_{x} \hbox {Se}$ (TM$=$Mn, Co and Fe)

Abstract

The structural, electronic, magnetic, thermal and elastic properties of Zn$_{1-x}$TM$_{x}$Se (TM $=$ Mn, Co and Fe) ternary alloys are investigated at x = 0, 0.25, 0.50, 0.75 and 1.00 in the zincblende (B3) phase. The calculations are performed using all-electron full-potential linearised augmented plane-wave (FP-LAPW) method within the framework of the density functional theory (DFT) and the generalised gradient approximation (GGA). The electronic and magnetic properties were performed using the modified Becke–Johnson potential combined with the GGA correlation (mBJ-GGA). The electronic structures are found to exhibit a semiconducting behaviour for Zn$_{1-x}$Mn$_{x}$Se and Zn$_{1-x}$Co$_{x}$Se and a half-metallic behaviour for Zn$_{1-x}$Fe$_{x}$Se alloys at all concentrations, while CoSe with $x = 1.00$ is found to exhibit a metallic behaviour. The calculated magnetic moment per substituted transition metal (TM) Mn, Co and Fe atoms for half-metallic compounds are found to be 2.5, 1.5 and 2 $\mu$$_{\mathrm{B}}$, respectively. The p–d hybridisation between the TM d- and Se p-states reduces the local magnetic moment of Mn, Co and Fe and induces small local magnetic moments on Zn and Se sites. In addition, we discuss the mechanical behaviour of binary and ternary compounds and all compounds studied here are mechanically stable.