(1-x)Bi_4Ti_3O_(12)-xK_(0.5)Na_(0.5)NbO_3铋层状陶瓷的结构与性能

Structure and Electrical Properties of(1-x)Bi_4Ti_3O_(12)-xK_(0.5)Na_(0.5)NbO_3 Bismuth Layer-structured Ceramics

采用固相法制备(1-x)Bi4Ti3O12-xK0.5Na0.5NbO3(BIT-KNN,x=0,0.05,0.10,0.15,0.20,0.30)铋层状压电陶瓷。用X射线衍射分析及扫描电镜等测试方法研究KNN掺量与BIT-KNN陶瓷晶体结构和电性能的关系。结果表明:所有陶瓷样品均为单一的正交相结构;随着KNN掺量的增加,陶瓷的晶粒尺寸变大,Curie温度θC呈下降趋势;KNN掺杂提高了样品的压电性能,压电常数d33随着KNN掺量的增加先增大后减小,相对介电常数εr表现相反的变化趋势;当x=0.10时,样品的电性能达到最佳值,即d33=11 pC/N,相对密度ρ=96.5%,机电耦合系数kp=4.52%,εr=151,介电损耗tanδ=0.45%,θC=619℃。

Bismuth layer-structured piezoelectric ceramics （1-x）Bi4Ti3O12-xK0.5Na0.5NbO3（BIT-KNN,x=0,0.05,0.10,0.15,0.20,0.30） were prepared by solid state reaction method. Crystal structure and electrical properties of BIT–KNN ceramics were characterized by various methods including X-ray diffraction and scanning electron microscopy. Results indicate that BIT–KNN materials possess a single orthorhombic structure. After KNN doping, grain size becomes larger and Curie temperature decreases. Piezoelectric properties of BIT-based ceramics were improved by addition of the KNN. With the increasing of the KNN dosage, piezoelectric properties d33 increase and then decrease. Relative dielectric properties exhibit contrasting properties. When x=0.10, the ceramic achieves an opti- mum performance： d33=11 pC/N, relative density ρ=96.5%, planar electromechanical coupling coefficient kp=4.52%, relative dielectric constant ε r=151, dielectric loss tan δ=0.45%, and Curie temperature θ C=619 ℃.