Sr_(0.3)Ba_(0.7)Nb_(2-y)Zr_yO_(6-y/2)陶瓷的微观结构和介电性能研究

Study on the microstructure and dielectric property of Sr_(0.3)Ba_(0.7)Nb_(2-y)Zr_yO_(6-y/2) ceramic

采用传统固相法制备了Sr0.3Ba0.7Nb2–yZryO6–y/2(SBNZ)(0≤y≤0.50)陶瓷。研究了Zr掺杂对SBNZ陶瓷微观结构和介电性能的影响。结果表明:y≤0.10时,Zr固溶到SBNZ晶体结构,使陶瓷晶格发生畸变并引起晶粒异常长大;y=0.30时,第二相Ba3ZrNb4O15的生成抑制了晶粒的异常长大。随Zr掺杂量的增加,SBNZ陶瓷的最大介电常数总体上呈先降后升的变化趋势,其室温介电常数则增加,另外,居里温度向室温移动。

Sr0.3Ba0.7Nb2-yZryO6-y/2（0≤y≤0.5, SBNZ） ceramics were prepared by the conventional solid state reaction method. The effects of zirconium doping on the microstructure and dielectric properties of the ceramics were investigated. The results show that, when y≤0.10, the doped zirconium incorporates into the crystal structure of the SBNZ ceramics, leading to the distortion of crystal lattice and the abnormal growth of grains of the ceramic; when y≥0.30, formation of the secondary phase Ba3ZrNb4O15 inhibits the abnormal growth of grains. With the increase of Zr content, the maximum permittivity （em） of the SBNZ ceramics decreases first and then increases, while its permittivity at room temperature increases and its Curie temperature shifts to room temperature.