Electronic structure and magnetic properties of Zn1−xTMxTe (TM = Fe, Co, Ni) for 0 ≤ x ≤ 1 alloys

Abstract

In this study, we employed Wu–Cohen generalized gradient approximation (WC-GGA) to calculate the structural stability, whereas the modified Becke and Johnson local-density approximation (mBJLDA) functional has been used to determine the electronic and magnetic properties of [Formula: see text] [Formula: see text] alloys in the [Formula: see text] range 0–1. Structural optimization in paramagnetic (PM), ferromagnetic (FM) and anti-ferromagnetic (AFM) orders has been done to check the state stability of the doped alloys and then verified with the calculated values of enthalpy of formation [Formula: see text]. The erections of enthalpies were negative which gave the evidence of structural stability in FM phase for all three alloys. Our calculated values of equilibrium lattice constants decreased by increasing the TM concentration, in [Formula: see text] [Formula: see text] alloys. We found ferromagnetism caused by the spin polarization of electron in TM-[Formula: see text] states in the studied alloys by analyzing the calculated band structure (BS), density of state (DOS) and magnetic moments. The calculated ferromagnetism was also explained from the Zener model. Due to the tetrahedral crystal field, the [Formula: see text]-state of TM splits into double [Formula: see text] and triple degenerate [Formula: see text] states and our calculated results show the strong pd interaction is only due to [Formula: see text]. Furthermore, we predict exchange splitting energies [Formula: see text] and [Formula: see text] and exchange constants [Formula: see text] and [Formula: see text]. Their calculated values are consistent with typical magneto-optical experiment. The magnetic moments of TM ions were reduced by increasing TM concentration in [Formula: see text] [Formula: see text] alloys, while trivial local magnetic moments at Zn and Te sites were also found.