Photoelectron diffraction investigation of the structure of the cleanTiO2(110)(1×1)surface

Abstract

The surface relaxations of the rutile $\mathrm{Ti}{\mathrm{O}}_{2}(110)(1\ifmmode\times\else\texttimes\fi{}1)$ clean surface have been determined by $\mathrm{O}\phantom{\rule{0.2em}{0ex}}1\phantom{\rule{0.3em}{0ex}}\mathrm{s}$ and $\mathrm{Ti}\phantom{\rule{0.2em}{0ex}}2{p}_{3∕2}$ scanned-energy mode photoelectron diffraction. The results are in excellent agreement with recent low-energy electron diffraction (LEED) and medium energy ion scattering (MEIS) results, but in conflict with the results of some earlier investigations including one by surface x-ray diffraction. In particular, the bridging O atoms at the surface are found to relax outward, rather than inward, relative to the underlying bulk. Combined with the recent LEED and MEIS results, a consistent picture of the structure of this surface is provided. While the results of the most recent theoretical total-energy calculations are qualitatively consistent with this experimental consensus, significant quantitative differences remain.