Effect of Twin-Plane Reentrant Edge on the Coarsening Behavior of Barium Titanate Grains |
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Authors: | Ho-Yong Lee Jae-Suk Kim Doh-Yeon Kim |
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Affiliation: | Division of Metallurgical and Materials Engineering, Sunmoon University, Chungnam, Asan 336–840, Korea;School of Materials Science and Engineering and Center for Microstructure Science of Materials, College of Engineering, Seoul National University, Seoul 151–742, Korea |
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Abstract: | When BaTiO3 ceramics were sintered at relatively low temperatures (≤1250°C), the grains with reentrant edges caused by a (111) double twin grew exclusively. As a result, a microstructure with a bimodal grain-size distribution composed of platelike large grains and fine matrix grains was obtained. In contrast, at the usual sintering temperature between 1250° and 1350°C, grains containing a (111) double twin did not exhibit any growth advantage. In this case, a coarse and uniform microstructure was obtained. When this coarse-grained specimen was further heat-treated at 1365°C, the grains possessing a double twin were observed to grow exclusively again. The results were explained in terms of a coarsening process controlled by two-dimensional nucleation. |
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Keywords: | barium titanate grain size temperature heat treatment |
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