Dielectric evaluation of electrically tunable Ba0.6Sr0.4TiO3 thick films prepared by screen printing
Dielectric evaluation of electrically tunable Ba0.6Sr0.4TiO3 thick films prepared by screen printing
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DOI：
10.1016/j.ceramint.2011.12.060
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发表时间：
2012-05
影响因子：
5.2
通讯作者：
Xiao-Fei Zhang;Qing Xu;Di Zhan;Hanxing Liu;Wen Chen;Duanping Huang
中科院分区：
文献类型：
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作者：
Xiao-Fei Zhang;Qing Xu;Di Zhan;Hanxing Liu;Wen Chen;Duanping Huang
以柠檬酸盐法制备的超细粉末为原料，采用丝网印刷法在氧化铝衬底上制备了Ba0.6Sr0.4TiO3厚膜。在1250°C下烧结的厚膜显示出立方钙钛矿结构和多孔微观结构。研究了厚膜的介电性能，并与致密陶瓷样品进行了比较。比较表明，多孔微结构的介电性能的显着影响。厚膜的多孔微结构导致介电常数降低，介电损耗增加，并降低了偏置电场下的介电非线性的场历史依赖性。厚膜的介电损耗的增加被解释为具有明显的界面极化和增强的导电性。与陶瓷样品相比，多孔厚膜保持了相当好的介电非线性，因为一个大的唯象系数。在室温下，该厚膜在零偏场和10 kHz下的介电常数为1270，介电损耗为1.4%，在57 kV/cm和10 kHz下的调谐率为60%，品质因数为43。
Ba0.6Sr0.4TiO3thick films were prepared on alumina substrates by screen printing using superfine starting powder derived from a citrate method. The thick film sintered at 1250°C showed a cubic perovskite structure and a porous microstructure. The dielectric properties of the thick film were investigated in comparison with dense ceramic specimen. The comparison indicates a significant effect of the porous microstructure on the dielectric properties. The porous microstructure of the thick film resulted in a lowered dielectric constant, an increased dielectric loss and a reduction of field history dependence for the dielectric nonlinearity under bias electric field. The increased dielectric dissipation of the thick film was interpreted with an appreciable interfacial polarization and an enhanced electric conduction. Compared with the ceramic specimen, the porous thick film maintained a reasonably good dielectric nonlinearity because of a large phenomenological coefficient. At room temperature, the thick film attained a dielectric constant of 1270 and a dielectric loss of 1.4% at zero bias field and 10kHz together with a tunability of 60% and a figure of merit of 43 at 57kV/cm and 10kHz.