Ab initio prediction of half-metallicity, stability and reconstruction in Cu3TaTe4 (1 0 0) surface

Abstract

This study reports DFT calculations on structural stability, electronic and magnetic properties of Cu3TaTe4(100) surface. Four possible symmetric terminations such as CuCu, CuTa, TeTe(1), and TeTe(2) are considered in cleaving the bulk crystal along (100) plane to form surface slab models. Surface energy calculation predicts that surface slab with CuCu termination is most stable and CuTa termination is most unstable. Meanwhile, the structural parameters after relaxation indicate that TeTe(2) surface could be most unstable due to its outward relaxation. Electron Localization Function calculations have shown that this seemingly contradicting results could be due to surface reconstruction in TeTe(2) surface, which significantly lowers the energy of the system. Electronic band structures of Cu3TaTe4(100) surface slabs exhibit transition from semiconducting nature in bulk crystal to either half metallic or fully metallic nature depending on the termination. The half metallic nature in CuCu and CuTa surface terminations provide promising theoretical data for future development of spintronic device.