随着目前开发无铅压电陶瓷元器件的大趋势，铋层状结构压电材料因其具有较高居里温度、低老化率、高击穿场强、低介电常数、高机械品质因数和优异的谐振频率稳定性，在高温、高频以及信息存储领域有着重要的应用前景而备受关注。但单一的铋层状结构压电材料因结构的特殊性存在难以实用化的缺点，因此本文从铋层状结构材料的自发极化机制出发，结合复相模型及分子动力学模型，采用分步合成工艺，选择性能优异的二层铋层状结构化合物SrBi2Nb2O9与钙钛矿结构Na0.5Bi0.5TiO3 进行复合，制备铋层状结构复相无铅压电陶瓷，从组分、基质颗粒以及复合工艺角度研究其高温下的介电与压电性能的作用规律，寻求适用于高温固态传感器和探测器的复相结构新材料。 采用分步固相烧结工艺成功制备了(1-x)SrBi2Nb2O9-xNa0.5Bi0.5TiO3(SBN-NBT，x=0.1, 0.2, 0.3, 0.4, 0.5)铋层状结构复相无铅压电陶瓷。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)及介电和压电测试系统等测试手段或技术对陶瓷样品的相结构、微观形貌和电性能进行表征。结果表明：样品均形成了钙钛矿结构相与铋层状结构相两相共存的复相结构，其中铋层状结构相随NBT引入量增多由SBN逐渐转变为二层与三层BLSF插层结构相，再转变为三层铋层状相。随着NBT组分的增加，相变峰向高温移动，铁电-顺电相变峰值介电常数随之减小，相应的介电峰半高宽的弥散度增大，铁电–顺电相变弥散程度增强，当x=0.4时样品弥散因子γ 达到1.95，表现出典型的弛豫铁电体的相变特征。当x=0.1时，样品的电性能达到最佳值：Curie温度TC、室温介电常数和d33分别达到474 ℃、177和13 pC·N–1。 其次，在上述分步固相烧结工艺基础上，改变预合成相粉体的制备工艺，以熔盐法制备的片状晶粒SBN/NBT以及溶胶-凝胶合成的超细晶粒SBN/NBT作为前驱预合成相，采用分步合成工艺制备SBN-NBT(x=0.1, 0.2, 0.3, 0.4)体系，探究SBN/NBT预合成相粉体制备工艺对复相陶瓷的结构及性能的影响。研究发现：粉体的制备工艺对相结构变化产生了明显的影响，熔盐法制备的片状晶粒SBN/NBT成功合成了SBN-NBT(x=0.1, 0.2, 0.3, 0.4)铋层状结构复相无铅压电陶瓷，其中铋层状结构相在x≤0.2时为SBN相，在x≥0.3时由SBN转变为2层与3层BLSF插层结构相。溶胶-凝胶制备的超细晶粒SBN/NBT则合成了铋层状结构固溶体相陶瓷样品，无钙钛矿相。随着NBT组分的增加，片状晶粒合成的复相陶瓷样品的Curie温度逐渐增加，Curie温度对应的相变峰峰值εr逐渐减小，铁电–顺电相变弥散程度逐渐增强，具有典型的介电弛豫特征。 为了进一步开发高温高性能的铋层状结构无铅压电陶瓷，基于TTG、复相陶瓷的优势，采用水热法在二维片状晶粒SrBi2Nb2O9的表面成功修饰了压电性能更加优异的0.8Na0.5Bi0.5TiO3-0.2K0.5Bi0.5TiO3纳米颗粒，无杂相生成。再经干压成型、固相烧结制备了(1-x)SrBi2Nb2O9-x(0.8Na0.5Bi0.5TiO3-0.2K0.5Bi0.5TiO3)(x=0.1, 0.3, 0.4, 0.5, 0.6,SBN-NKBT)系列复相陶瓷。研究发现：当 x=0.1时样品就已经出现了的钙钛矿结构相NKBT，而铋层状结构相随NKBT引入量增多由SBN逐渐转变转变为三层铋层状相，无中间相二层与三层插层结构相。随着NBT组分的增加，居里温度由440℃逐渐增大600℃以上，铁电-顺电相变峰值介电常数随之减小，相应的介电峰半高宽的弥散度增大，铁电–顺电相变弥散程度增强。当x=0.1时，样品的电性能达到最佳值：居里温度Tc 达到487℃，室温介电常数为123，d33达到17 pC·N-1。

Bismuth layer-structured ferroelectrics (BLSF) as lead-free piezoelectric device are especially attractive technology, owing to their high Curie temperature, low dielectric constant and low aging rate, high breakdown voltage, high mechanical quality factor, the excellent stability of the resonance frequency, and the broad application prospects in the area of high temperature, high frequency, and information storage. However, it is difficult for the single bismuth layered materials to apply in industry. In this study, new type of bismuth layer/perovskite composite phase materials was synthesized via two-step synthesis to introduce perovskite phase N0.5Bi0.5TiO3 to SrBi2Nb2O9. We analyzed the grain, component and composite process of the composite phase materials to reveal the relation between structure characteristics and electric properties, which is important to develop new materials used in the high temperature solid state sensors and detectors. (1–x)SrBi2Nb2O9–xNa0.5Bi0.5TiO3(SBN–NBT, x=0.1, 0.2, 0.3, 0.4, 0.5) ceramics were prepared via a step ceramic processing. The crystal structure, microstructure and electrical properties were investigated. The coexisted structures of the bismuth layer structured phase and the perovskite Na0.5Bi0.5TiO3 phase in the ceramics were determined by dielectric spectrum, analysis, X-ray diffraction, and scanning electron microscopy. The phase transition characteristics were investigated. The results show that two-layered SBN forms two-layered and three-layered BLSF inserted layer compounds, and subsequently form three-layered BLSF compounds. The structural, dielectric and piezoelectric properties depending on the NBT content were analyzed. The phase transition peaks shift to a high temperature area, the peak value ɛr reduces and the dispersion degree of peak FHWM riess with the increasing of the NBT content. According to the dielectric response behaviors, normal ferroelectric– paraelectric phase transition to a relaxor-like behavior occurs when NBT content increases. When x=0.4 and γ=1.95, the sample shows the phase transition characteristics of typical relaxation ferroelectrics. As a result, optimized comprehensive electrical properties are obtained in the 0.9SBN–0.1NBT composition, i.e., TC=474 ℃, dielectric constant εr=177 and d33=13 pC/N. Basing on the composite ceramics synthesis process, we change the synthesis process of the SBN/NBT phase powders. The SBN/NBT powders were prepared via molten-salt and sol-gel method. And then SBN-NBT were fabricated by the step ceramic processing, as is used to investigate the effects of different powder synthesis process on the microstructures and dielectric properties of the SBN-NBT composite ceramics. The results showed that the coexistence structures of the bismuth layer structured phase and the perovskite phase have been determined using the molten-salt powers. The phase transition characteristics suggested an evolution from two-layered SBN to two-layered and three-layered BLSF inserted layer compounds when x=0.3. The single bismuth layer structured solid solution has been prepared using the sol-gel powers. With the increasing of the NBT content, phase transition peaks of composite ceramics shift to high temperature, the peak values ɛr reduce and the dispersion degree of peak FHWM increase. In order to further develop bismuth layer structure lead-free piezoelectric ceramics with high performance, we used the superiority of the TGG and Composite Ceramics to fabricate the SBN-NKBT bismuth layer/perovskite powders by the nanoparticles NKBT modified on the surface of lamellae SBN via the hydrothermal method. Then, the SBN-NKBT(x=0.1, 0.3, 0.4, 0.6, 0.8, SBN-NKBT) composite ceramics have been prepared via solid-phase sintering. The crystal structure, microstructure and electrical properties were systematically investigated. The coexistence structures of the bismuth layer structured phase and the perovskite phase have been determined in these ceramics using dielectric spectrum and X-ray diffraction, scanning electron microscope. The phase transition characteristics have been investigated and the results suggested an evolution from two-layered SBN to three-layered BLSF compounds and the disappearance of two-layered and three-layered BLSF inserted layer compounds.With the increasing of the NKBT content, phase transition peaks shift to high temperature, the peak values ɛr reduce and the dispersion degree of peak FHWM increase. Dielectric response behaviors suggested an evolution from normal ferroelectric–paraelectric phase transition to a relaxor-like behavior with the increase of NBT content.