钛酸铋钠Na0.5Bi0.5TiO3(简称NBT)是A位复合离子结构钙钛矿型铁电体。本论文采用传统电子陶瓷制备方法在钛酸铋钠钾系无铅陶瓷固溶不同的钙钛矿结构组元，优化了准同型相界组成。通过结构分析探讨了钛酸铋钠钾系陶瓷的介电弛豫特性、相变特性以及材料的组成对铁电、压电性能的作用规律，并获得了具有高压电活性与铁电性的无铅压电陶瓷新材料组成体系。 在钛酸铋钠钾、钛酸铋钠钾钡准同型相界的基础上，通过固溶钛酸铋锂，制备了NKBT-LBT、NKBBT-LBT两大体系陶瓷。研究发现：在其组成范围内，两组体系均形成了单一的钙钛矿结构。通过XRD谱确定出NKBT-LBT、NKBBT-LBT系列陶瓷的准同型相界(MPB)范围分别是0.08≤x≤0.10和0.06≤x≤0.12；LBT的引入能够有效降低陶瓷的烧结温度，显著地细化晶粒； LBT组分的引入有助于改善其铁电性，剩余极化强度Pr从7 μc/cm2 增至15 μc/cm2 (NKBT-LBT)且材料的压电活性也显著提高，在准同型相界处，压电常数d33 达到了最高值(145 pC/N)。 为进一步研究钛酸铋钠钾系材料在A、B双位复合置换时性能变化。选取钛酸铋钠钾陶瓷基础上固溶NaNbO3、KNbO3和LiNbO3，制备了致密的NKBT-NN、NKBT-KN和NKBT-LN陶瓷。在所研究的组成范围内，两组材料体系均形成了单一的钙钛矿结构。KNbO3的引入起到了细化晶粒的作用，弥散相变特征明显。NaNbO3的引入有效的改善了钛酸铋钠钾系材料的压电、铁电性能，压电常数d33提高到131pC/N。随着LiNbO3含量的增加，材料的矫顽场显著降低从29.1kV/cm 降至19.7kV/cm；LiNbO3的引入对材料的介电性能影响明显，材料的铁电-反铁电相变峰也随着LN含量的增加而具有明显的移峰效应，同时反铁电-顺电相变峰则表现为压峰效应，材料表现出明显的弛豫特性。 为了进一步探索钛酸铋钠钾系材料结构与性能关系，引入钙钛矿结构BiFeO3与BiCoO3，获得了具有高压电性能的(1-x)Na0.4K0.1Bi0.5TiO3-xBiFeO3和(1-x)Na0.4K0.1Bi0.5TiO3-xBiCoO3无铅陶瓷，其准同型相界(MPB)范围分别为0.02≤x≤0.06和0.01≤x≤0.02。BiFeO3的引入有效的降低了体系的烧结温度，其压电常数d33先增大后减小，在准同型相界处，压电常数d33为127 pC/N(x=0.06)。随着BiCoO3的引入量加大，NKBT-BC陶瓷的弛豫度随逐渐增强。微量的BiCoO3可以提高该体系陶瓷的压电性能，其压电常数在x=0.02时达到最大值，d33=119 pC/N。

Bismuth Sodium Titanate Na0.5Bi0.5TiO3 (abbreviated NBT) is a ferroelectric ceramic that has the A-site complex perovskite type structure. In this paper, NBT-based ceramics with optimized the morphotropic phase boundary compositions were prepared by the conventional solid state reaction. The dielectric relaxation feature, phase transition feature and material composition on the role of the law of ferroelectric and piezoelectric properties been investigated by analysised the structure of perovskite structure of components. The new lead-free piezoelectric materials with high piezoelectric and ferroelectric activity were prepared. The lead-free piezoelectric ceramics NKBT-LBT and NKBBT-LBT were prepared by solid solution with Li0.5Bi0.5TiO3 into Na0.4K0.1Bi0.5TiO3 and Na0.44K0.04Bi0.48Ba0.04TiO3 ceramics. In the study of their composition range, the X-ray diffraction (XRD) analysis revealed that the two sets of ceramic systems form a single perovskite structure, and the morphotropic phase boundary (MPB) between the rhombohedral and tetragonal phases of NKBT-LBT was identified in the composition range of 0.08≤x≤0.10, and the morphotropic phase boundary of NKBBT-LBT was identified in the composition range of 0.06≤x≤0.12. With the increasing of LBT content，the sintering temperature and the grain size decreasd. The ferroelectric properties of the NKBT ceramics are further improved with the introduction of the LBT content. And the remnant polarization Pr increases from 7 μc/cm2 to 15 μc/cm2. The piezoelectric activity is enhanced with an increase in LBT content and piezoelectric constant d33 reaches 145 pC/N at the morphotropic phase boundary . In order to further study the material properties change of NBT-based ceramics, the dense lead-free piezoelectric ceramics NKBT-NN、NKBT-KN and NKBT-LN were prepared by solid solution with NaNbO3、KNbO3 and LiNbO3 into NKBT-based ceramics. In the study of their composition range, the X-ray diffraction (XRD) analysis revealed that the three sets of ceramic systems form a single perovskite structure. The grain size decrease with the increase of KN content, the diffuse phase transition characteristics is significant. The dielectric and ferroelectric properties are further improved with introduce of NaNbO3 component and the piezoelectric constant was increased to d33=131 pC/N. With the increasing of LiNbO3 amount, the coercive field declined obviously from 29.1kV/cm to 19.7kV/cm. At the same time, the ferroelectric–antiferroelectric transition temperature moved significant form high temperature to low temperature and antiferroelectric-paraelectric transition peak was repressed obviously. In order to further the exploration of the relationship between the material structure and properties of NBT-based ceramic, the the high piezoelectric activity ceramics NKBT-BF and NKBBT-BC were prepared by solid solution with BiFeO3 and BiCoO3. For NKBT-BF ceramics, the morphotropic phase boundary (MPB) lies in composition range of x=0.02~0.06. The sintering temperature significantly decreases of BF content. The piezoelectric constant d33 increased firstly and then decreased.When x=0.06, the maximum of d33 was 127pC / N. For NKBT-BC ceramics, the morphotropic phase boundary (MPB) lies in a narrow composition range of x=0.01~0.02.The relaxation degree gradually increase with the introduce of BC. The piezoelectric activity is enhanced with an increase in BC content and piezoelectric constant d33 reaches 119 pC/N at x=0.02.