Search for fully spin-polarized semiconductor heterostructures:The candidate (Zn,Co)O

The authors suggest geometrical arrangements in (Zn,Co)O multilayered structures which maximize the spin polarization densities. The theoretical argument is supported by electronic structure calculations based on a two-band effective mass model adapted to describe these systems and solved self-consistently with the aid of Poisson's equation. The exchange correlation, the strain terms, and the magnetic interactions are all included in the Hamiltonian. From their results a set of parameters can be determined to maximize the presence of spin-polarized charge distributions inside or outside the nonmagnetic layers, which enhances the transition temperature to ferromagnetism or the carrier mobility in the system.