Half-metallic ferromagnetism in I 2–VI compounds with non-magnetic dopants

Abstract

First-principles calculations based on the tight-binding linear muffin-tin orbital (TB-LMTO) method were performed to investigate the occurrence of spin polarization in the alkali metal oxides (M 2O) [M: Li, Na, K, Rb] in antifluorite (anti- CaF 2-type) structure with non-magnetic (N, P, As, Sb and Bi) dopants. The calculations reveal that non-magnetic substitutional doping at anion site can induce stable half-metallic ferromagnetic ground state in I 2–VI compounds. Total energy calculations show that the antifluorite ferromagnetic state is energetically more stable than the antifluorite non-magnetic state at equilibrium volume. Ground state properties such as equilibrium lattice constant and bulk modulus were calculated. The calculated magnetic moment is found to be 1.00 μ B per dopant atom. The magnetic moment is mainly contributed by p orbitals of dopant atom.