Grain-Growth Behavior during Stepwise Sintering of Barium Titanate in Hydrogen Gas and Air |
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Authors: | Yang-Il Jung Si-Young Choi Suk-Joong L Kang |
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Affiliation: | Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea |
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Abstract: | To study the effect of oxygen partial pressure on grain growth in BaTiO3, TiO2-excess samples have been sintered in air with and without a prior H2 heat treatment. Without prior H2 treatment, abnormal grain growth occurs below and above the eutectic temperature ( T e). An introduction of H2 treatment before air sintering, however, increases the average grain size and suppresses the formation of abnormal grains during subsequent air sintering below and above T e. This H2 treatment effect has been explained in terms of a decrease of the driving force for the growth of faceted grains below a critical value for formation of abnormal grains. The observed grain-growth behavior under various atmospheres demonstrates the possibility of having various microstructures via control of oxygen partial pressure and initial grain size. |
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Keywords: | barium titanate dielectric materials/properties grain growth |
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