Structural Transitions and Microwave Dielectric Properties of Ba2−2xSr2xSmSbO6 Double Perovskites
Structural Transitions and Microwave Dielectric Properties of Ba2−2xSr2xSmSbO6 Double Perovskites
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DOI：
10.1111/j.1551-2916.2011.05064.x
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发表时间：
2012-05
影响因子：
3.9
通讯作者：
Y. Zhou;Cailan Tian;Siqin Meng;Zhenxing Yue;Long-tu Li
中科院分区：
文献类型：
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作者：
Y. Zhou;Cailan Tian;Siqin Meng;Zhenxing Yue;Long-tu Li
研究了Ba 2 - 2xSr 2xSmSbO 6（x = 0-1）陶瓷的结构和微波介电性能。使用X射线粉末衍射、透射电子显微镜和拉曼光谱分析相变。所有结构都是有序的双钙钛矿结构，并证实了Ba 2 − 2xSr 2xSmSbO 6体系中存在一系列组分诱导的相变：Fm-3 m → I2/m → P21/n。在微波频率（9-11 GHz）下测量陶瓷的介电性能。随着x的增加，介电常数（er）从20.7逐渐变化到16.0，品质因子（Q × f）首先从86 500 GHz下降到x = 0.4时的最小值，然后略有增加到93 000 GHz，谐振频率温度系数（τf）从+25降至-50 ppm/°C。从相变的角度讨论了Ba 2 - 2xSr 2xSmSbO 6的组成、结构与微波介电性能之间的关系。
Structures and microwave dielectric properties of Ba2−2xSr2xSmSbO6 (x = 0–1) ceramics were studied in this article. The phase transitions were analyzed using X-ray powder diffraction, transmission electron microscopy, and Raman spectroscopy. All structures are proved to be ordered double perovskites, and a series of composition-induced phase transitions are confirmed in the Ba2−2xSr2xSmSbO6 system via the sequence: Fm-3m → I2/m → P21/n. Dielectric properties of the ceramics were measured at microwave frequencies (9–11 GHz). With the increase of x, the dielectric constant (er) varies gradually from 20.7 to 16.0, the quality factor (Q × f) decreases first from 86 500 GHz to a minimum value at x = 0.4 and then increases slightly to 93 000 GHz, and the temperature coefficient of resonant frequency (τf) decreases from +25 to −50 ppm/°C. The relationships between composition, structure, and microwave dielectric properties in Ba2−2xSr2xSmSbO6 were discussed from the phase transition consideration.