Formation of micro-crystals on the (100) surface of SrTiO3 at elevated temperatures

Droplet-like features and regularly shaped micro-crystals appear on the (10 0) surface of single-crystals of stoichiometric and doped SrTiO3 as a resul t of heat treatment around 1000-1100 degrees C under ambient pressure. Seco ndary ion mass spectrometry, atomic force microscopy and X-ray photoemissio n are employed to characterize the morphology of the modified surface. The results provide evidence of an accumulation of SrOx on the surface in a liq uid form and subsequent recrystallization as SrO on prolonged annealing. Th e phenomena are discussed in relation to the restructuring in the near-surf ace region and the loss of material at the temperatures employed, as eviden t from thermogravimetrical measurements. (C) 2000 Elsevier Science B.V. All rights reserved.