Half metallicity and magnetic stability of sp-electron superlattices in rock-salt structure: A first-principles study

Density functional calculations were performed to study the structural, electronic, and magnetic properties of sp-electron half-metallic super lattices (KS)(1)/(CaS)(1), (RbS)(1)/(SrS)(1), and (CsS)(1)/(BaS)(1) (001) in rock-salt structure. All the superlattices are found to be spin polarized, and the calculated band structure suggests a 100% polarization of the conduction carriers. The p-p hybridization is shown to be essential for the formations of localized orbitals and spin-splitting. The half-metallic electronic structure will be destroyed upon an excessive lattice compression, accompanying with a metallic transition. Moreover, the analysis of the orbital-decomposed partial density of states and spin density reveal that S atoms in different layers of the superlattice show distinct polarization directions. Discussion of volume-conserving deformations further demonstrates the stability of half metallicity in sp-electron superlattices. (C) 2014 Elsevier Ltd. All rights reserved.