Comparative study of half-metallic ferromagnetic behaviour in ZnO monolayer doped with boron and carbon atoms

Abstract

Electronic band structures of B- and C-doped ZnO monolayers (ML) at high doping concentration are studied based on spin-polarized plane-wave DFT with Projector Augmented Wave Potentials and Generalized Gradient Approximation. Our results show that both the B- and C-doped structures at 3.13% impurity atom per supercell exhibit half-metallic ferromagnetic behaviour due to the spin-polarized 2p orbitals of the dopant atom, which are localized within the energy gap of the host lattice. A net magnetic moment of 1μB and 2μB are, respectively, found in the B- and C-doped structures mainly due to the partially filled dopant atom 2 p orbitals. Due to ferromagnetic coupling, magnetic moments from the neighbouring Zn atoms and the subsequent O atoms also contribute to the net magnetic moment. At a higher doping concentration of 6.25% impurity atom per supercell, both the materials completely transformed into metal. It is also found that while C doping maintains its ferromagnetic property at this doping concentration, the B-doped ZnO ML becomes antiferromagnetic metal. Our findings would provide valuable theoretical data for material scientists in fabrication of the doped ZnO ML in laboratory