铋基焦绿石材料是一种具有焦绿石结构性能优异的新型介电陶瓷材料，本文在高介电常数(Bi1.5Zn0.5)(Zr1.5Nb0.5)O7与(Bi1.5Zn0.5)(Ti1.5Nb0.5)O7焦绿石材料基础上，通过选取不同离子对其A位与B位进行部分与完全取代，采用Rietveld结构精修获得精确的晶体结构信息，进而研究不同种类的离子取代对焦绿石材料的结构与性能的影响。为开发温度稳定型特征的焦绿石介电体，优选具有正负温度系数特征的焦绿石单相体系，进行复相组成设计，开发极具应用价值的新型NP0高频介质。主要研究结果如下： (1) 通过二价离子对A位Zn离子的取代，研究了(Bi1.5Zn0.5-xMgx)(Zr1.5Nb0.5)O7 (x=0.1, 0.2, 0.3, 0.5) (BZMZN)与(Bi1.5M0.5)(Zr1.5Nb0.5)O7 (M= Zn、Mg、Ca、Sr )体系，当Mg离子引入A位时，产生了微量Bi12MgO19相；随着Mg离子取代量的增加，材料的介电常数减小，这是由于Mg离子的引入使得整体极化率变小所导致的，而BZMZN系列材料弛豫度先增加后下降，这与A位离子的种类以及微区分布不均匀性及排列有序性有关； (Bi1.5M0.5)(Zr1.5Nb0.5)O7系列试样介电常数基本相同，从材料总极化率与BO6八面体结构的相互关系给出了解释；BZMZN与(Bi1.5M0.5)(Zr1.5Nb0.5)O7系列材料在低温下均表现出介电弛豫特性，对于本研究体系首次采用不同物理模型包括：Arrenhnius模型、VF方程与新玻璃模型拟合之后认为系列焦绿石低温介电弛豫特性与材料中原子尺度上无序与不均匀分布的A位离子与O′位离子的本征跃迁有关。 (2) 采用五价阳离子对B位Nb离子进行取代，结合Rietveld结构精修研究了(Bi1.5Zn0.5)(Ti1.5M0.5)O7 (M=Nb, Ta, Sb) (BZTM)体系，三组试样均形成了立方焦绿石单相结构，扫描电镜照片显示陶瓷体微结构致密、晶粒形状规则，相比Nb与Ta，Sb取代试样易于晶体生长，故其晶粒尺寸较大；BZTM试样的介电性能表现出明显的差异，结合精修数据，BZTS具有较低的介电常数与小温度系数，源于其骨架结构-BO6八面体网络畸变度最大；系列试样在低温范围内都表现出明显的介电弛豫特性，基于Debye模型的拟合认为低温介电弛豫特型与O′-A-O′链的本征跃迁过程有关；系列试样交流电导率在测试温度范围内呈现分段上升的趋势，对比Arrhenius方程拟合结果，分析认为不同温度段电导率的主要机制不同，同时结合精修数据分析，Sb的引入使得焦绿石陶瓷的高温电导率显著上升，这是由于其晶体结构中存在大量氧空位，在高温下定向迁移形成高温电导。 (3) 通过优选具有正、负温度系数特征的焦绿石单体系，根据李氏定则理论计算，制备了： 0.3(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7-0.7(Bi1.5Zn0.5)(Zr1.5Nb0.5)O7 (0.3BZN-0.7BZZN)、0.5(Bi1.5Zn0.5)(Zn0.5Ta1.5)O7-0.5(Bi1.5Zn0.5)(Zr1.5Nb0.5)O7 (0.5BZT-0.5BZZN)、0.6(Bi1.5Zn0.5)(Zn0.5Sb1.5)O7-0.4(Bi1.5Zn0.5)(Zr1.5Nb0.5)O7 (0.6BZS-0.4BZZN)与0.2(Bi1.5Zn0.5)(Ti1.5Nb0.5)O7-0.8(Bi1.5Zn0.5)(Zr1.5Nb0.5)O7 (0.2BZTN-0.8BZZN)复相焦绿石材料，X射线衍射谱显示其主峰出现分峰现象，说明晶体结构相似、但晶格参数不同的两个单相已形成焦绿石复相结构；介电温度测试结果表明，在温度范围-55~125℃之内，系列试样的温度稳定性都有所改善，尤其是BZN-BZZN体系介电常数高(~126)，介电损耗较小(~0.004)，其介电常数温度系数符合国际NP0超稳定级温度稳定型电容器材料的标准，标志着其在振荡器、谐振器以及高频电路中的耦合电容等相关领域有着良好的应用前景。

Bismuth-based pyrochlores is a kind of new dielectric ceramics with excellent performance, on the basis of the composition of (Bi1.5Zn0.5)(Zr1.5Nb0.5)O7 and (Bi1.5Zn0.5)(Ti1.5Nb0.5)O7 with high dielectric constant, different ions were chosen to occupy A and B site in pyrochlore structure partially and completely. The influence of the structure and the properties by the occupation of different ions was researched combined with the accurate micro structure information abtained by Rietveld refinement. Moreover, in order to develop the dielectric pyrochlores with temperature stable characteristics, the complex phase compositon of pyrochlores was prepared by selecting suitable single phase fundamental system which has positive and negative temperature coefficient. The main results are as follows: (1) The compositions with formula (Bi1.5Zn0.5-xMgx)(Zr1.5Nb0.5)O7 (x=0.1, 0.2, 0.3, 0.5) (BZMZN) and (Bi1.5M0.5)(Zr1.5Nb0.5)O7 (M= Zn、Mg、Ca、Sr ) were studied. There is traces of the second phase Bi12MgO19 when Zn sites were substituted by the partial and complete Mg. With increasing amount of Mg substitution, the dielectric constant decrease slightly because of the decrease of the total polarizability. The relaxed degree of series BZMZN pyrochlores increases first and decreases when Zn was completely substituted by Mg, it is related to the type of ions in A sites and inhomogeneous distribution in local regions. The total polarizability and mutual relationship of BO6 octahedra were used to explain that series samples of (Bi1.5M0.5)(Zr1.5Nb0.5)O7 have the basically same dielectric constant. The dielectric relaxation was found in all BZMZN and (Bi1.5M0.5)(Zr1.5Nb0.5)O7 pyrochlores at about -150℃. The relaxation behavior was fitted by Arrenhnius model, VF model and new glass model and the relaxation mechanism was further deduced with the bond-valence theory, the relaxation is related to inhomogeneous distribution of A site atoms and the local intrinsic hopping of atoms in the A and O′ positions among several local potential minima. (2) Quaternary pyrochlores doped by the pentavalent cations with the formula (Bi1.5Zn0.5)(Ti1.5M0.5)O7 (M=Nb, Ta and Sb) have been synthesized and studied. The XRD patterns show that all of the three samples give single phase. SEM photos show all the samples have well sintering condition and regular grain shape, compared with Nb and Ta, Sb substituted sample is easy to crystal growth, so the grain size of BZTS is maximum. The refined data by GSAS program and the bond valence theory were used to analyze different dielectric properties with occupation of different ions in B site. The small dielectric constant of BZTS is due to the total polarizability, especially from the contribution of BO6 octahedra distortion degree, and weak correlation when Sb placed into the center of the octahedra would also result in small αε. The relaxation of BZTM series pyrochlores is related to inhomogeneous distribution of A site atoms and the local intrinsic hopping of atoms in the A and O′ positions among several local potential minima based on the fitting results. The conduction study shows that defect-related weakly bonded electrons hopping among the local region are reckoned to be the main charge carriers in the low temperature range. When it comes to the moderate temperature range, oxygen vacancies migration was thermally activated as the carriers mechanism, and the different activation energies is related to the association and the disassociation of massive complex defects. It is reckoned that there are the most structure defects in the BZTS by the refined data which should provide more oxygen vacancies and free oxygen ions to participate the conduction, leading to the σ value being the largest of the three samples. (3) Through choosing the single phase pyrochlores with positive and negative temperature coefficient. Alternative compositons 0.3BZN-0.7BZZN, 0.5BZT-0.5BZZN, 0.6BZS-0.4BZZN and 0.2BZTN-0.8BZZN were prepared according to the Lichtenecker law. The peak split of the strongest peak from XRD data shows that the complex phase was formed, but there are trace of the second phase in 0.3BZN-0.7BZZN. The results of dielectric temperature test indicate that temperature stability of sample is improved in the range of -55~125℃ for industrial applications, especially 0.3BZN-0.7BZZN system with high dielectric constant (~126), low dielectric loss (~0.004) and temperature coefficient close to zero which is up to the international standard of NP0 so called ultra stable temperature stable type capacitor materials. It could be applied widely to oscillator, resonator and the coupling capacitors in the high frequency circuit.