摘要钛酸铋钠(Bi0。5Na0。5)TiO3(BNT)无铅压电陶瓷是压电陶瓷材料中的一个重要的代表。它具有压电性能好、铁电性能强和介电常数低等特性。但是BNT基压电陶瓷的矫顽场过高（室温下Ec 高达73kV/cm），极化困难造成其压电活性低。此外在高温条件下烧结，原料易挥发，造成了BNT陶瓷的烧结致密性、物理化学性质的稳定性较差。这些不足导致纯BNT无铅压电陶瓷无法满足实用化的要求。

本文将利用水热合成法制备BNT基无铅压电陶瓷，主要研究在其二元体系基础上添加第三组元BT，针对其三元体系(1-x)(Na0。82K0。18)0。5Bi0。5TiO3-xBa0。5TiO3进行研究，对x取0、0。03、0。05、0。06、0。07、0。08值时制备陶瓷样品，对x=0。06的样品分别在1020℃、1050℃、1080℃和1120℃下烧结，其他样品均在1080℃烧结，得到的陶瓷样品进行相关的表征和性能测试，如对其进行XRD物相分析，利用扫描电镜观察样品表面的微观形貌，对其介电性能、压电性能和铁电性能等进行测试。

通过以上研究得到：向二元体系中加入BT时，降低了陶瓷样品的矫顽场，此时Ec=36kV/cm；对x=0。06的样品在不同温度下烧结得到的样品发现在1080℃得到较高的致密度为98。3%；BNKT-BT体系在x的含量为0。06时，该体系具有最大压电系数d33为167pC/N，相对介电常数εr为630，介电损耗tanδ为0。028，剩余极化强度Pr为39μC/cm2。它的传导机制较为符合空间电荷限制电流（SCLC）机制。87839

毕业论文关键词：无铅压电陶瓷 钛酸铋钠 水热合成 压电性能

毕业设计说明书外文摘要

Title  Preparation and Properties of ternary BNT based lead-free piezoelectric ceramics

Abstract BNT Lead-free piezoelectric ceramics is an important representative of a piezoelectric ceramic material。 It has good piezoelectric properties, ferroelectric properties of strong performance and low dielectric constant。 But BNT based piezoelectric ceramic high coercive field (Ec at room temperature up to 73kV/cm), the difficulties caused by piezoelectric polarization activity is low。 Also in high temperature sintering, volatile raw material, resulting in a poor stability BNT ceramics sintered density, physical and chemical properties。 These deficiencies lead to pure BNT lead free piezoelectric ceramics can not meet the practical requirements。

This article was prepared by hydrothermal synthesis BNT based lead-free piezoelectric ceramics, the main research in its binary systems on the basis of adding a third component BT, for its ternary system (1-x) (Na0。82K0。18) 0。5 Bi0。5TiO3-xBa0。5TiO3 studies, preparation of ceramic samples taken 0,0。03,0。05,0。06,0。07,0。08。 x values for sample with x = 0。06, respectively, at 1020 ℃, 1050 ℃, 1080 ℃ and 1120 ℃ under sintering, other samples were sintered at 1080 ℃, the ceramic sample was subjected to the relevant characterization and performance tests, such as its XRD phase analysis, morphology by scanning electron microscopy of the sample surface, its dielectric properties, ferroelectric and piezoelectric properties performance testing。

Through the above research was: the binary system when added to BT, reducing the coercive field of ceramic samples, then Ec = 36kV/cm; for x = 0。06 sample at different temperatures obtained sintered samples found at 1080 ℃,the higher density of 98。3%; BNKT-BT system in x of 0。06, the system has a maximum piezoelectric coefficient d33 of 167pC/N, a relative permittivity εr of 630, a dielectric loss tanδ of 0。028, residual polarization Pr is 39μC/cm2 。Its transmission mechanism more in line with the space-charge-limited current (SCLC) mechanism。

Keywords  Lead-free piezoelectric ceramics，BNT，Hydrothermal synthesis， piezoelectric

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