Spin polarization calculations and related properties of the surfaces of CoVTe alloy and interface with a BeTe semiconductor

Abstract

Previous calculations indicate that the CoVTe half-Heusler alloy appears half-metallic (HM) with spin polarization equal to 100%. We predict the spin polarisation and related alloy properties for the CoVTe (001), (111), and (110) surfaces and interface with a BeTe semiconductor. All the calculations were based on the generalized gradient approximation (GGA) with the Clb structure, using a first-principles investigation. We find a weak relaxation with (001) terminations, meaning the two terminations are stable and have stronger relaxations with the V (111) surface. The (001) V–Te surface has half-metallicity (HM) preserved with the HM energy gap of 0.22 eV and full spin polarisation, so the surface is useful for applications in the field of spintronics when using thin films, while other surfaces showed a high spin polarisation with values of 85–96%. For The CoVTe/BeTe interface demonstrates a weak relaxation for both structures. For VTe–Te*, the HM is destroyed and the minority spin is close to the Fermi level, with a higher spin polarization equal to 93%. The VTe–Be configuration retains HM, suggesting it is a good candidate for spintronic applications. The values of the magnetic moment for the surface and interface are calculated because these values may change when used as a thin film.