High-resolution synchrotron-radiation photoemission characterization for atomically-controlled SrTiO3(001) substrate surfaces subjected to various surface treatments

The chemical properties and electronic structures of atomically flat SrTiO3(001) substrates with various surface treatments have been investigated by high-resolution synchrotron-radiation photoemission spectroscopy. We have found that an annealing process causes the segregation of Sr oxides at the TiO2-terminated surface and that the TiO2-terminated surface is more stable than the SrO terminated one. We demonstrate that the use of chemical etching process is effective as a removal technique for Sr oxides accumulating on TiO2-terminated surfaces and that the adding of a reetching process after annealing in an O-2 environment is one of the best methods to obtain well defined and nearly perfect substrate surface. (C) 2004 American Institute of Physics.