双层钛酸锶钡陶瓷的制备与研究

Preparation and research of double-layer Barium Strontium Titanate ceramics

采用固相法分别制备施主掺杂陶瓷、受主掺杂陶瓷及双层钛酸锶钡陶瓷．施主掺杂选择呈现明显半导化的0．15％（摩尔比，下同）的La2O3；受主掺杂选择铁电性的0．15%的Fe2O3．XRD测试表明多种复合粉体均为钙钛矿结构；SEM结果显示：制备的双层钛酸锶钡陶瓷整体致密度较高，层间存在厚度接近30μm的过渡区域．介电温谱测试表明：掺La^3＋与掺Fe^3＋的介电峰分别在温度10℃和80℃处，双层钛酸锶钡陶瓷的介电常数在10～80℃温度区间明显平滑，介电常数和介电损耗均与电容串联模型的计算结果十分吻合．此双层复合方法提供制备高温度稳定性和功能复合陶瓷的有效实验手段．

Double-layer Barium Strontium Titanate（BST） composite ceramics doped with donor and acceptor, respectively, were fabricated by the solid-state reacting method The donor dopant of BST ceramics was selected with 0.15 % （mol, similarly hereinafter） La2O3 for a semiconducting. The acceptor dopant of BST ceramics was selected with 0.15% Fe2O3 for a normal ferroelectric. XRD tests confirmed the perovskite structure for all the doped compositions. SEM results exhibited that the double-layer BST ceramics had a transition region, nearly 30 μm, between two layers, which connected two parts tightly. Dielectric measurements showed that dielectric peaks of La^3＋ and Fe^3＋ doped BST ceramics were at 10℃ and 80 ℃, respectively. Dielectric constant of the double-layer BST ceramics was very flat between 10 ℃ and 80 ℃. The calculated results of dielectric constant and loss by connecting two parts in series were in well coincident with experimental results. This double-layer composite method provides an effective preparation approach for ceramics with high temperature-stability, and multi-functions.