REFLECTION HIGH-ENERGY ELECTRON-DIFFRACTION STUDY ON THE SRTIO3 SURFACE-STRUCTURE

This paper reports a reflection high-energy electron diffraction investigation of the surface structures of the (001) and (110) crystal faces of SrTiO3 given various surface treatments. The as-polished surface has a (1 X 1) unreconstructed structure on both the (001) and (110) crystal faces. The vacuum annealed surface has a two-domain (2 X 1) superstructure on the (001) face and a (4 X 4) structure on the (110) face. The oxygen annealed surface has two superstructures on the (001) face: a two-domain (square-root 13 X square-root 13-R33.7-degrees) structure and a c(6 X 2) structure, and a (4 X 2) or a (4 X 4) structure on the (110) face. Of these surfaces, the oxygen annealed surface has the highest quality.