Investigation of Triple Extrinsic Origins of Colossal Dielectric Constant in CaCu3Ti4O12 Ceramics
Publication in refereed journal

香港中文大學研究人員

引用次數
替代計量分析
.

其它資訊
摘要Polycrystalline CaCu3Ti4O12 (CCTO) ceramics were prepared via a wet-chemistry method. Complex dielectric permittivity spectroscopy was performed on CCTO ceramics. We noticed that three distinct Maxwell-Wagner relaxations were clearly separated and could be associated with three mechanisms of extrinsic origins. These relaxations, which take place at three kinds of internal insulating barrier layers and at their respective frequency regions, explain the observed colossal dielectric constant at room temperature. In addition, the associated migrations of charge carriers manifest at the same frequency regions in ac conductivity spectra as the corresponding dielectric relaxations. We provided a complete and consistent scenario to elucidate the dielectric responses of CCTO and compare it with previous studies. The resistivity obtained from a semicircular arc of the impedance spectroscopy at low frequencies was interpreted as the surface resistivity instead of the grain boundary resistivity.
著者Yuan WX, Hark SK, Mei WN
期刊名稱Journal of The Electrochemical Society
出版年份2010
月份1
日期1
卷號157
期次5
出版社Electrochemical Society
頁次G117 - G120
國際標準期刊號0013-4651
語言英式英語
關鍵詞calcium compounds; ceramics; copper compounds; dielectric relaxation; grain boundaries; permittivity; titanium compounds
Web of Science 學科類別Electrochemistry; ELECTROCHEMISTRY; Materials Science; Materials Science, Coatings & Films; MATERIALS SCIENCE, COATINGS & FILMS

上次更新時間 2020-26-11 於 00:34