AN STM, XPS AND LEED INVESTIGATION OF THE BATIO3(111) SURFACE

The BaTiO3(111) surface is investigated with STM, XPS and LEED. Vacuum -annealing at 1470 K gives terraces with a (root 3 x root 3)R30 degree s superstructure. The reduction of the surface is probed with XPS thro ugh the appearance of shoulders in the Ti 2p photoemission lines due t o the formation of Ti3+ centers. Annealing in oxygen at 1470 K produce s terraces with (1 x 1) and (2 x 2) superstructures. which are reverte d not into a (root 3 x root 3)R30 degrees superstructures by vacuum-an nealing but into a mixture of terraces of (2 x 2) and (root 3 x root 3 )R30 degrees superstructures. (C) 1998 Elsevier Science B.V. All right s reserved.