Ferromagnetism in zigzag GaN nanoribbons with tunable half-metallic gap

• DOI: 10.1016/j.commatsci.2016.02.012
• Publication Date: 2016-02-27T13:10:05Z
• Authors: Kai-Wu Luo; Liang Xu; Ling-Ling Wang; Quan Li; Zhiyong Wang
• Keywords: Zigzag; Half-metal

Abstract Using first-principles calculations, we investigate the electronic and magnetic properties of pristine and hydrogen-terminated zigzag GaN nanoribbons (ZGaNNRs). When the nitrogen edge of the ZGaNNRs is passivated, regardless of the gallium edge, the ZGaNNRs are wide band-gap semiconductors. However, when the nitrogen edge is unpassivated, the ZGaNNRs have 100% spin polarization around the Fermi level and become half metals. It is the strong interaction between the N-2p orbitals and Ga-4p orbitals that leads to the half-metallic ferromagnetism. What’s more, with the ribbons width increases, the half-metallic gap of only gallium edge hydrogenated ZGaNNRs decreases monotonously in a wide range. The tunability of half-metallic gap for ZGaNNRs can be applied to electronic and spintronic devices with wide or specific energy gaps.