Electronic and magnetic properties of zinc blende half-metal superlattices

Zinc blende half-metallic compounds such as CrAs, with large magnetic moments and high Curie temperatures, are promising materials for spintronic applications. We explore layered materials, consisting of alternating layers of zinc blende half-metals, by first principles calculations, and find that superlattices of (CrAs)1(MnAs)1 and (CrAs)2(MnAs)2 are half-metallic with magnetic moments of 7.0mB and 14.0mB per unit cell, respectively. We discuss the nature of the bonding and half-metallicity in these materials and, based on the understanding acquired, develop a simple expression for the magnetic moment in such materials. We explore the range of lattice constants over which half-metallicity is manifested, and suggest corresponding substrates for growth in thin film form.