Crystal structure and dielectric properties of Bi₂O₃-CaO-Nb₂O₅ compounds

详细信息    查看全文

• 作者：Libin Gao ; ^{biner167@sina.com} ; Ke Tang ; Jiaming Xu ; Zhengrui Xu
• 关键词：Dielectric properties ; Pyrochlore ; Bismuth based dielectric materials ; Crystal structure ; Low dielectric loss
• 刊名：Materials & Design
• 出版年：2017
• 出版时间：15 February 2017
• 年：2017
• 卷：116
• 期：Complete
• 页码：109-114
• 全文大小：1261 K
• 卷排序：116

文摘

The Bi2O3-CaO-Nb2O5 (BCN) materials were prepared by solid-state reaction. The BCN pyrochlores exhibited a layered structure with general formula of CaBi2Nb2O9 when the sintering temperature below 1100 °C, and the sample in a nearly pure phase at 1100 °C. The structure of BCN ceramics was gradually transformed into Ca2Nb2O7 pyrochlore structure with further increasing the sintering temperature. The dielectric properties varied with structures. The BCN ceramic sintered at 1100 °C exhibited excellent dielectric properties with a dielectric constant of ~ 110 and a dielectric loss of ~ 0.001. The dielectric constants of all the ceramics were independent with the measurement frequency (100 Hz–1 MHz) at room temperature. However, the dielectric loss decreased dramatically at low frequency and then increased slightly with increasing frequency. The temperature dependence of dielectric properties of BCN ceramics was also investigated. The BCN materials with a Ca2Nb2O7 pyrochlore structure were more sensitive to the temperature than that with a CaBi2Nb2O9 structure.