First principles study of the relative stability and electronic properties of the VN/GaN/VN interlayer

Using first principles total-energy calculations within the framework of density functional theory, the relative stability and the structural and electronic properties of a VN/GaN/VN interlayer in sodium chloride (NaCl), cesium chloride (CsCl), nickel arsenide (NiAs), zinc-blende, and wurtzite structures were studied. The calculations were carried out using a method based on pseudopotential, employed exactly as implemented in Quantum-ESPRESSO code. From total energy minimization, it was found out that the global energy minimum of VN/GaN/VN is obtained for the wurtzite structure. Additionally, at high pressure, our calculations show the possibility of phase transition from the wurtzite to the NaCl structure. For the wurtzite phase, the density of states analyses revealed that the interlayer exhibits a half-metallic behavior with a magnetic moment of 2.0 µβ/V-atom. This property essentially comes from the polarization of states V-d and N-p crossing of the Fermi level. Due this property, the interlayer can potentially be used in the field of spintronics as spin injectors.   Key words: Density functional theory (DFT), interlayers, structural and electronic properties.