ONE-DIMENSIONAL ORDERING ON THE (1)OVER-BAR012)LINBO3 SURFACE

The structure of the (1012BAR)LiNbO3 surface annealed in air at a temp erature of 950-1150-degrees-C is studied by RHEED. Solid or discrete c ircular arcs are observed in diffraction patterns in the [1011BAR] azi muth and sharp streaks in the [1210BAR] azimuth. The origin of these d iffraction patterns are the linear chains of point defects arising on the surface in the [1011BAR] direction under annealing.