教師資料查詢 | 類別: 期刊論文 | 教師: 高惠春KAO, HUEY-CHUEN (瀏覽個人網頁)

標題:Phase Transition and the Thermal Activated Ordering of the Ions with Pyrochlore Phase in Ln2 Zr2 O7 (Ln = Sm, Eu)
學年99
學期1
出版(發表)日期2010/08/31
作品名稱Phase Transition and the Thermal Activated Ordering of the Ions with Pyrochlore Phase in Ln2 Zr2 O7 (Ln = Sm, Eu)
作品名稱(其他語言)
著者Chiu, Chih-Wei; Lee, Yu-Hsuen; Sheu, Hwo-Shuenn; Kao, Huey-Chuen. I.
單位淡江大學化學學系
出版者臺北市:中國化學會
著錄名稱、卷期、頁數Journal of the Chinese Chemical Society=中國化學會會誌 57(4)pt.B, pp.925-931
摘要Two series of samples, Sm2Zr2O7 and Eu2Zr2O7, were prepared by the polymeric citrate precursor method and calcined in static air between 7001450˚C for 24 h. Nano-size particles obtained were larger with increasing calcination temperatures. Sm2Zr2O7 and Eu2Zr2O7 samples have fluorite phase if they are prepared at temperatures lower than 1000 and 1100˚C, respectively. On the other hand, if the samples are prepared at temperatures higher than 1100 and 1150˚C, they have pyrochlore phase. Phase transition temperature depends on the ionic radius ratio of R(Ln3+)/R(Zr4+). The larger the ratio, the lower the transformation temperature is. Quenched samples have unit cell a-axis increases with increasing preparation temperatures. The amount of cation antisite in the disordered pyrochlore phase decreases with increasing calcination temperatures. Activation energies calculated on the log (σ‧T) vs. (1/T) for the Sm2Zr2O7 and Eu2Zr2O7 on the cation ordering process are 0.30(1) and 0.39(2) eV, and on the O(3) site are 0.70(9) and 1.2(2) eV, respectively. O2 is much bigger than R3+ so that more energy is required to overcome the hopping potential. Activation energy increases as the ionic radius ratio of theR(Ln3+)/R(Zr3+) decreases due to the decreasing of the unit cell volume.
關鍵字
語言英文
ISSN0009-4536; 2192-6549
期刊性質國內
收錄於SCI;
產學合作
通訊作者Kao, Huey-Chuen. I.
審稿制度
國別中華民國
公開徵稿
出版型式,紙本
相關連結
SDGs
Google+ 推薦功能,讓全世界都能看到您的推薦!