STRUCTURE-ANALYSIS OF SRTIO3(111) POLAR SURFACES

The structure change of SrTiO3 (111) polar surfaces was studied as a f unction of atmosphere, by atomic force microscopy, Auger electron spec troscopy (AES) and X-ray photoelectron spectroscopy (XPS). The SrTiO3 (111) surfaces annealed in oxygen gas had a trench structure, while th e surfaces annealed in argon gas formed large triangular terraces. The surfaces annealed in air, i.e., in intermediate oxygen partial pressu re. consisted of complicated self-similar triangles with different siz es, forming a fractal shape called Sierpinski's gasket. The XPS analys es indicated that surface oxygen states were different depending on th e annealing atmosphere.