Study of the topmost surface structure of a y-cut LiNbO3 single crystal with coaxial impact collision ion scattering spectroscopy (CAICISS)

The topmost surface structures of a y-cut LiNbO3 single crystal were studied with coaxial impact collision ion scattering spectroscopy (CAICISS). The observed CAICISS spectra of the azimuthal intensity variation of Nb atoms of that had mirror plane symmetry which was unexpected from the space group of LiNbO3 (R3c, C3v 6) itself. By the simulation of CAICISS, it was strongly suggested that Nb atoms at the topmost few layers of y-cut LiNbO3 single crystal were rearranged to give a mirror plane of symmetry in their three-dimensional atomic con®guration rather than to form other related oxides. # 2001 Elsevier Science B.V. All rights reserved