First-principles study on the electronic and magnetic properties of the Zn0.75Mo0.25M(M = S,Se,Te)

Abstract

The geometrical, electronic and magnetic properties of the Zn[Formula: see text]Mo[Formula: see text]M (M[Formula: see text]=[Formula: see text]S, Se and Te) have been studied by spin-polarized first-principles calculation. The optimized lattice constants of 5.535, 5.836 and 6.274 Å for M[Formula: see text]=[Formula: see text]S, Se and Te are related to the atomic radius of 1.09, 1.22 and 1.42 Å for S, Se and Te atoms, respectively. The Zn[Formula: see text]Mo[Formula: see text]M are magnetic half-metallic (HM) with the spin-down conventional band gaps of 2.899, 2.126 and 1.840 eV, while the HM band gaps of 0.393, 0.016 and 0.294 eV for M[Formula: see text]=[Formula: see text]S, Se and Te, respectively. At the Fermi level, the less than half-filled Mo-[Formula: see text] orbital hybridizated with the less M-[Formula: see text] orbital contributes only spin-up channel leading Zn[Formula: see text]Mo[Formula: see text]M an HM ferromagnetism. The tetrahedral crystal field formed by adjacent three Zn atoms and one M atom splits the spin-up channel (majority spin) of Mo-[Formula: see text] orbital into three-fold degenerate [Formula: see text] states at the Fermi level and double degenerate [Formula: see text] [Formula: see text] states below the Fermi level. The exchange splitting energies of the Zn[Formula: see text]Mo[Formula: see text]M are −2.611, −2.231 and −1.717 eV for M[Formula: see text]=[Formula: see text]S, Se and Te, respectively. The results provide an useful theoretical guidance for Zn[Formula: see text]Mo[Formula: see text]M applications in spintronic devices.