(Bi_(2-x)Zn_x)(Ti_(2-x)Nb_x)O_7陶瓷的结构与介电性能

Structure and Dielectric Properties of (Bi_(2-x)Zn_x)(Ti_(2-x)Nb_x)O_7 Ceramics

研究了（Bi2--xZnx）（Ti2--xNbx）O7（0．4≤x≤1．0）陶瓷材料的结构与介电性能。X-射线衍射结果表明，该组分体系在950～1100℃烧结，可得到单相立方焦绿石结构陶瓷。扫描电子显微镜观察样品形貌发现，x越大，晶粒尺寸越大。室温介电性能的测试表明，在1MHz条件下，随x值的增大，介电常数从218下降到122，损耗为（1～4）×10^-4。介电温谱测试发现，该组分体系在低温下出现明显的介电弛豫峰，峰形随x增大逐渐宽化。微波特性的测试表明，在谐振频率2～3GHz，样品的品质因数与谐振频率之积Q×f为112～158GHz。

The structure and dielectric properties of （Bi2--xZnx）（Ti2--xNbx）O7（0.4≤x≤1.0） ceramics were investigated. All samples sintered at 950~1 100 ℃ exhibit a single cubic pyrochlore structure according to X-ray diffraction analysis. Scanning electron microscope micrographs indicate that the grain size increases with the increase of x value. The dielectric properties tests at room temperature show that the dielectric constant at 1 MHz decreases from 218 to 122 with the increase of x value and the dielectric loss remains in the level of （144） ×10^-4. Dielectric temperature spectra reveal that all compositions show a typical dielectric relaxation behavior and the dielectric peak flattens with the increase of x value. The product of quality factor and frequency （Q× f ） is in the range of 112- 158 GHz at the resonant frequency of 2~3 GHz by microwave characteristic tests.