Publication Date:
2015-09-11
Description:
SrTiO 3 (STO) is attracting lots of research interests due to the rich physics and properties presented at its surfaces and the interfaces of STO with other transition metal oxides. Based on density functional theory methods, we have investigated the influence of hydrogen (H) atoms adsorption at the (001) surface of STO on the geometrical and electronic structures of the surface. We find that H adsorption induces significant antiferrodistortive (AFD) distortion of TiO 6 octahedra at the surface. By calculating H adsorption energy, we show that AFD distortion makes a significant contribution to the stability of H adsorbed STO surfaces. The calculated energy position of O-H bond states by hybrid functional method is 9.9 eV below Fermi level, in agreement with experimental value of 10 eV. The electrons donated by H atoms first occupy several d xy bands and then start to fill in degenerate d yz /d xz bands, indicating the metallization of initially insulating STO. The band splitting and occupy sequence calculated here are consistent with recent angle-resolved photoemission spectroscopy experiments. Our results reveal that H adsorption changes the atomic and electronic structures and thus induce fascinating properties at the surface of STO.
Print ISSN:
0021-8979
Electronic ISSN:
1089-7550
Topics:
Physics
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