標題: Microstructure and crystal phases of praseodymium oxides in zinc oxide varistor ceramics
作者: Lee, YS
Liao, KS
Tseng, TY
電子工程學系及電子研究所
Department of Electronics Engineering and Institute of Electronics
公開日期: 1-九月-1996
摘要: The effect of sintering temperature on the microstructure and crystal phases of the intergranular praseodymium oxides in ZnO varistor ceramics was investigated using transmission electron microscopy and high-resolution electron microscopy. The ZnO grains were three-dimensionally separated from the intergranular praseodymium oxides. On the basis of microdiffraction analyses of the intergranular layer, the phase transformation from fcc-Pr6O11 into hcp-Pr2O3 was found when the sintering temperature increased from 1300 degrees to 1350 degrees C. The defect reaction equation and the decrease of donor concentration with increasing sintering temperature can verify the certainty of phase transition during the liquid-phase sintering observed by transmission elecron microscopy. Additionally, on the basis of the small variations of the breakdown voltage per grain boundary, the number of active grain boundaries is not a dominant factor for the donor concentration dependence on the sintering temperature.
URI: http://dx.doi.org/10.1111/j.1151-2916.1996.tb08986.x
http://hdl.handle.net/11536/149316
ISSN: 0002-7820
DOI: 10.1111/j.1151-2916.1996.tb08986.x
期刊: JOURNAL OF THE AMERICAN CERAMIC SOCIETY
Volume: 79
起始頁: 2379
結束頁: 2384
顯示於類別:期刊論文