顺电态下掺铝钛酸锶钡陶瓷微结构和介电调谐性能

Microstructure and Dielectric Tunable Properties of Al_2O_3-doped Barium Strontium Titanate in the Paraelectric State

用传统的电子陶瓷工艺合成Ba_(0.6)Sr_(0.4)TiO_3(BST),研究Al_2O_3掺杂对钛酸锶钡陶瓷微结构、介电及调谐性能的影响.通过XRD及SEM的研究表明,Al^(3+)能够完全的进入到Ba_(0.6)Sr_(0.4)TiO_3晶格内部形成固溶体,同时陶瓷的结晶程度变好,颗粒大而均匀.陶瓷的介电损耗明显减小,介电常数有所降低,调谐率明显上升,其中,掺杂量为0.8wt％Al_2O_3时,陶瓷样品具有最佳的介电调谐性能.

Al2O3-doped Ba0.6Sr0.4TiO3(BST) ceramics were prepared by using conventional ceramic technology. The samples were analysed by SEM and XRD. The results indicate that Al3+ behaves as a grain-growth helper below a certain doping level and also the dopants have entered the unit-cell maintaining the perovskite structure of the solid solution. The dielectric constant and dissipation factor decrease and the tunability increases by, addition of Al2O3. The specimen at doping level of 0.8wt% has the optimal overall dielectric properties.