| Structural and optical studies of high dielectric constant (Na0.5A0.5)Cu3Ti4O12 (A=La and Bi) | |
|---|---|
| 學年 | 96 |
| 學期 | 2 |
| 出版（發表）日期 | 2008-07-01 |
| 作品名稱 | Structural and optical studies of high dielectric constant (Na0.5A0.5)Cu3Ti4O12 (A=La and Bi) |
| 作品名稱（其他語言） | |
| 著者 | Liang, K. C.; Liu, H. L.; Yang, H. D.; Mei, W. N.; 林大欽; Ling, D. C. |
| 單位 | 淡江大學物理學系 |
| 出版者 | Institute of Physics (IOP) |
| 著錄名稱、卷期、頁數 | Journal of Physics: Condensed Matter 20(27), pp.275238(8 pages) |
| 摘要 | We report x-ray powder diffraction and temperature-dependent infrared reflectivity measurements of (Na0.5La0.5)Cu3Ti4O12 and (Na0.5Bi0.5)Cu3Ti4O12 in order to investigate the origin of their lower room-temperature dielectric constants in comparison with the giant value of CaCu3Ti4O12. Substituting Ca with Na/La or Na/Bi is found to decrease all Ti–O–Ti angles by the TiO6 octahedra tilts, resulting in an increase of the local structural disorder on the Na/La and Na/Bi compounds. Further, several infrared-active phonon modes show a broadening in their linewidths, reflecting that the coherency in these vibrational modes is degraded by disorder. Additionally, the lowest-frequency mode of the Ca material is observed to strengthen dramatically at low temperatures, but to a lesser extent in the Na/La and Na/Bi compounds. These results suggest the important role of the local structural disorder on the anomalous low-frequency dielectric response in these materials. |
| 關鍵字 | |
| 語言 | en |
| ISSN | 0953-8984 |
| 期刊性質 | 國外 |
| 收錄於 | |
| 產學合作 | |
| 通訊作者 | |
| 審稿制度 | 否 |
| 國別 | GBR |
| 公開徵稿 | |
| 出版型式 | ,電子版 |
| 相關連結 |
機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/50346 ) |
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