First-principles study on the structural, electronic, and magnetic properties of bulk and (001) surface of RuS2

摘要

The spin-polarized first-principles calculations were used to study the structural, electronic, and magnetic properties of bulk and (001) surface of RuS2. The bulk RuS2 was a nonmagnetic semiconductor and the valence band maximum was contributed by Ru-4d(t(2g)) states near M-point while the conduction band minimum was contributed by antibonding S-3p(sigma*) states at Gamma-point, resulting an indirect band gap of 1.29 eV. The Ru-layer terminated and double S-layers terminated RuS2 (001) surfaces had the broken Ru-S bond and broken S-S dimer while the single S-layer terminated RuS2 (001) surface had broken Ru-S bond but remained S-S dimer. The Ru-layer terminated and double S-layers terminated RuS2 (001) surfaces were magnetic semiconductor with a small band gap of 0.30 eV and magnetic metal, respectively, while the single S-layer terminated RuS2 (001) surface was still a nonmagnetic semiconductor with a band gap of 0.97 eV. The highest surface energy indicated the Rulayer terminated RuS2 (001) surface had the most catalytically active among the three terminated RuS2 (001) surfaces.