標題: Second Phase and Defect Formation in Bi0.5Na0.5-xKxTiO3 Ceramics
作者: Chen, Pin-Yi
Chou, Chen-Chia
Tseng, Tseung-Yuen
Chen, Haydn
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-Jun-2010
摘要: The second phase and defect formation mechanisms of [Bi-0.5(Na1-xKx)(0.5)]TiO3 (BNKT100x) ceramics were investigated using electron microscopy, X-ray photoelectron spectroscopy (XPS), and electrical properties measurement. Experimental results indicated that second phase formation induces Bi-rich regions and compositional inhomogeneity within the matrix owing to the thermodynamic stability of potassium titanate. The Ti valence transition for BNKT ceramics sintered in air might be ascribed to the formation of secondary phase and low oxygen atmosphere, rather than simply attributed to the volatilization of bismuth. Li substitution at the A-site in BNKT ceramics suppresses formation of the second phase and Ti valence transition. Appropriate atmosphere control during material processing, such as sintering at higher oxygen pressure, and post oxidization annealing suppress oxygen vacancies and titanium valence transition, and therefore decrease the leakage current as well as improve electrical properties. (C) 2010 The Japan Society of Applied Physics DOI: 10.1143/JJAP.49.061506
URI: http://dx.doi.org/10.1143/JJAP.49.061506
http://hdl.handle.net/11536/149968
ISSN: 0021-4922
DOI: 10.1143/JJAP.49.061506
期刊: JAPANESE JOURNAL OF APPLIED PHYSICS
Volume: 49
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