Ferromagnetic materials in the zinc-blende structure

Abstract

New materials are currently sought for use in spintronics applications. Ferromagnetic materials with half metallic properties are valuable in this respect. Here we present the electronic structure and magnetic properties of binary compounds consisting of $3d$ transition metals and group V elements, viz., P, Sb, and As in the zinc-blende structure. We demonstrate that compounds of V, Cr, and Mn show half metallic behavior for appropriate lattice constants. By comparing the total energies in the ferromagnetic and antiferromagnetic structures, we have ascertained that the ferromagnetic phase is stable over the antiferromagnetic one. Of the different compounds studied, the Cr based systems exhibit the strongest interatomic exchange interactions, and are hence predicted to have the highest critical temperatures. Also, we predict that VAs under certain growth conditions should be a semiconducting ferromagnet. Moreover, critical temperatures of selected half metallic compounds have been estimated from mean field theory and Monte Carlo simulations using parameters obtained from a ab initio noncollinear, tight binding linearized muffin-tin orbital method. From a simple model, we calculate the reflectance from an ideal MnAs/InAs interface considering the band structures of MnAs and InAs. Finally, we present results on the relative stabilities of MnAs and CrSb compounds in the NiAs and zinc-blende structures, and suggest a parameter space in substrate lattice spacings for when the zinc-blende structure is expected to be stable.