二价阳离子取代的Ba2-xRxNdNb5O16瓷料结构与性能的研究

以Ba2NdNb5O16为基，通过二价阳离子的取代，探讨取代物对Ba2-xRxNdNb5O16瓷料介电性能与结构的影响，实验结果表明，Sr^2 ,Ca^2 Mg^2 取代使资料的相对介电常数εr随取代量显著增大，温度系数αε也发生明显变化，变化幅度与取代物离子半径密切相关，XRD、SEM微观结构分析可以推断，实验瓷料为四方晶系钨青铜结构，因取代物离子半径差异而占据五边形A2和四边形A1间隙的几率不同，引起介电性能明显变化。

Structure and Dielectric Property of Ba2-xRxNdNb5O16 Ceramics Substituted by Bivalent Positive Ion

R2+ (R = Sr, Ca, Mg) are respectively introduced to substitute the Ba2+ on the basic of Ba2-xNdNb5O16. The influences of the substitutes on the dielectric property and the structure of ceramics are investigated. The experiment results show that with the increase of the quantity of the substitutes, er increases markedly and ae changes evidently, of which the extent is related with the radius of ions of the substitutes. X-ray diffraction analysis and Scan Electron Microscope analysis suggest that Ba2-xRxNdNb5O16 is tetragonal tungsten structure. The difference of radius of substitute ions are the causes of the difference probability of holding pentagon lacuna(A2) and quadrangle lacuna(A1), which leads to evident variety of dielectric property.