Half-metal effect on the MnAs/InP (0 0 1)-(2 × 4) interface

Spin-polarized first-principles total-energy calculations have been done in order to investigate the epitaxial growth of MnAs on the InP (0 0 1) surface. The epitaxial growth is carried out on the mixed dimer reconstructed InP (0 0 1)-(2 × 4) surface. The initial stage of the MnAs epitaxial growth is stable under P-rich and intermediate conditions. Also, InAs growth is stable under In-rich conditions. We have deposited extra MnAs layers on top of the structure to build four stable interfaces: one constructed by 50% MnP and 50% InP, an ideal formed by MnP, the ideal interface of InAs and an interface built by alternating layers of InAs and InP. Under In-rich conditions, the epitaxial growth of InAs remains stable. We have investigated the magnetic and electronic properties of the four stable interfaces. Results show semiconductor-ferromagnetic interfaces in all cases, with the structure having spin up magnetization. The density of states shows that the interfaces are half-metallic, where the conduction channels of majority spin come from the P-p and Mn-d orbitals, and the minority spin exhibits an energy gap. Our results suggest that MnAs may allow the generation of spin-polarized current in InP semiconductors, which makes this system suitable for applications in spintronic devices.