Evidence of Half-Metallicity in the AlP/CrP (001) Interface: A First-Principles Study

The structural, electronic, and magnetic properties of the epitaxial growth of zinc-blende CrP onto the AlP (001) surface are investigated by first-principles spin-polarized calculations. Early stages of the epitaxial growth are investigated by the deposit of a Cr monolayer onto the Al and P-terminated surfaces. The results show that the deposit onto the P-T surface is feasible, with the surface acquiring antiferromagnetic characteristics. Once two CrP layers are deposited, the system becomes ferromagnetic. Also, the surface displays a half-metallic property, which is preserved when the interface is well defined. The thermodynamic stability of the initial stages of the epitaxial growth and the subsequent formation of the interface are investigated by the surface and interface formation energy formalisms. Our results show that the interface is stable under Al-rich and Cr-poor conditions. At the same time, five AlP (001) surface reconstructions are stable in the rest of the chemical potential region, as previously reported. We also calculated the Curie temperature, finding a value of 743 K. Our results demonstrate that the epitaxial growth of the zinc-blende CrP onto the AlP (001) substrates is feasible, and the properties of the CrP/AlP(001) system are suitable for implementation in spintronic devices that operate at room temperature.