Secondary Abnormal Grain Growth and(111) Twin Boundaries in <TEX>$BaTiO_3$</TEX>

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J. Korean Ceram. Soc. > Volume 36(12); 1999 > Article

Journal of the Korean Ceramic Society 1999;36(12): 1310.

$BaTiO_3$에서 이차 비정상 입성장과 (111)쌍정판

김재석, 이종봉, 허태무¹, 이호용¹, 김도연²

선문대학교 공과대학 재료금속공학부
¹선문대학교 공과대학 재료금속공학
²서울대학교 재료공학부 재료미세조직 창의 연구단

Secondary Abnormal Grain Growth and(111) Twin Boundaries in $BaTiO_3$

ABSTRACT

Two serial abnormal grain growths were observed to occur in BaTiO3 above the eutectic temperature of 1332$^{circ}C$. The first one occurred during liquid-phase sintering of a BaTiO3 powder compact containing a small amount of excess TiO2, as in the conventional sintering. When the sintered sample which consisted of 70${mu}{textrm}{m}$ size grains after the completion of the abnormal grain growth was annealed again at 13$65^{circ}C$ some exceptionally large grains appeared and grew to several millimeters. We call these two abnormal grain growths primary (PAGG) and secondary abnormal grain growth (SAGG) repectively. Almost all the secondary abnormal grains contained(111) double or single twins and the shape of matrix grains was angular. The presence of the twins in the abnormally large may suggest that the twin-plane re-entrant edge (TPRE) growth mechanism was operative for the SAGG

Key words: Abnormal grain growth (111) Double twin, Twin-plane re-entrant edge(TPRE), $BaTiO_3$