1673-159X

CN 51-1686/N

掺杂氧位Bi1.5ZnNb1.5O7陶瓷结晶化学与介电性能

Phase Structure, Crystal Chemistry and Dielectric Property of Oxygen-site Doped Bi1.5ZnNb1.5O7 Ceramics

  • 摘要: 用F-替代氧离子O2-,采用固相反应法制备Bi1.5-xCaxZnNb1.5O7 (0.00≤x≤0.30,简称C-x)、Bi1.5-x CaxZnNb1.5O7-yFy(0.00≤ x ≤0.20,简称CF- x)陶瓷样品,研究F-添加的缺陷补偿形式、替代位置,以及对Ca2+掺杂的Bi1.5ZnNb1.5O7 (简称α-BZN)陶瓷的相结构、结晶化学和介电性能的影响。结果表明:F-的引入降低了Ca2+在α-BZN陶瓷的固溶度,替代八面体BO6的氧位;在等量Ca2+掺杂的情况下,引入F-进入体系后,样品的介电常数减小,介电损耗下降,这与F-引入α-BZN陶瓷后,四面体A4O′键价和比Ca2+单独掺杂时高一致;F-替代导致介电峰值温度均向高温移动,这可能与F-的添加导致激活能增加有关。

     

    Abstract: By substituting F- for O2-, Bi1.5-xCaxZnNb1.5O7 (0.00≤x≤0.30, abbreviated as C-x), Bi1.5-xCaxZnNb1.5O7-yFy (0.00≤x≤0.20, abbreviated as CF-x) ceramics samples were prepared by conventional solid-state reaction method. The way of defect compensation, doping position substitution position, the influence of F- dopant on phase structure, crystal chemistry and dielectric properties of Ca-doped Bi1.5ZnNb1.5O7 (abbreviated as α-BZN) ceramics samples were investigated. The results revealed that F- incorporation declined the solid solution of Ca2+ in α-BZN, and F- was dissolved into the oxygen site of BO6 octahedral. In the same amount of Ca2+ dopant, with F- incorporation, both the dielectric constant and the dielectric loss decreased, which was consistent to the bond valence sums for A4O′. Compared with Ca2+ doping, the bond valence sums for A4O′ of F- and Ca2+ co-doping increased. The shift of the dielectric constant peak to higher temperature could be associated with the increase in activation energy due to the addition of F-.

     

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