Faceting behavior of an asymmetric SrTiO3 Σ5 [001] tilt grain boundary close to its defaceting transition

• Published in: Acta materialia Vol. 51; no. 15; pp. 4583 - 4588
• Main Authors: Lee, Sung Bo, Sigle, Wilfried, Rühle, Manfred
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 03.09.2003; Elsevier Science
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; Exact sciences and technology; Grain and twin boundaries; Grain boundary faceting-defaceting transition; High-resolution transmission electron microscopy (HRTEM); Metals. Metallurgy; Physics; Strontium titanate bicrystal; Structure of solids and liquids; crystallography; High-resolution transmission electron microscopy (HRTEM); Grain boundary faceting-defaceting transition; Strontium titanate bicrystal; Grain boundaries; Crystal defects; Bicrystals; Dielectric materials; Tilt boundaries; Experimental study; Faceting; Transmission electron microscopy; Structium titanate bicrystal; Strontium titanates; Microstructure
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/S1359-6454(03)00295-7

Using high-resolution transmission electron microscopy (HRTEM), an asymmetric Σ5 [001] grain boundary in SrTiO3 with an inclination of 2.5° away from the symmetric (310) plane was studied. A defaceting transition is observed between 1500 and 1600 °C. From 1520 to 1570 °C, the grain boundary is faceted into the symmetric (310) and asymmetric (100)//(430) planes. At 1590 °C, the grain boundary is observed to be defaceted, which implies that the defaceting occurs between 1570 and 1590 °C. The faceted structure observed between 1500 and 1590 °C is interpreted in terms of the step free energy of the asymmetric (100)//(430) facet orientation. The faceting-defaceting transition is schematically represented as the temperature evolution of the equilibrium grain shape.