Temperature dependence of faceting in Σ5(310)[001] grain boundary of SrTiO3

Using high-resolution electron microscopy (HREM), temperature dependence of faceting of an asymmetric Sigma5 grain boundary (GB) in SrTiO3 is observed. The bicrystal samples have been fabricated by ultra-high vacuum diffusion bonding and heat-treated between 1100 and 1600 degreesC. Below 1300 degreesC, this GB facets into symmetric (310) and asymmetric (100)//(430) GB planes. At 1300 degreesC, in addition to the asymmetric facet, the symmetric [210) facet appears: three different facets are thus observed at this temperature. At 1400 and 1500 degreesC, the asymmetric facet disappears and the two kinds of symmetric facets remain. At 1600 degreesC, faceting disappears and the G13 becomes defaceted. The faceting/defaceting transition behavior of the GB is interpreted in terms of the Wulff plot and its corresponding equilibrium crystal shape. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.