QUASI-IDEAL STRONTIUM-TITANATE CRYSTAL-SURFACES THROUGH FORMATION OF STRONTIUM HYDROXIDE

In recent years, well-defined and nearly perfect single crystal surfac es of oxide perovskites have become increasingly important. A single t erminated surface is a prerequisite for reproducible thin film growth and fundamental growth studies. In this work, atomic and lateral force microscopy have been used to display different terminations of SrTiO3 . We observe hydroxylation of the topmost SrO layer after immersion of SrTiO3 in water, which is used to enhance the etch-selectivity of SrO relative to TiO2 in a buffered HF solution. We reproducibly obtain pe rfect and single terminated surfaces, irrespective of the initial stat e of polished surfaces and the pH value of the HF solution. This appro ach to the problem might be used for a variety of multi-component oxid e single crystals. True two-dimensional reflection high-energy electro n diffraction intensity oscillations are observed during homo epitaxia l growth using pulsed laser deposition on these surfaces. (C) 1998 Ame rican Institute of Physics. [S0003-6951(98)03546-3].