与其他压电材料相比, 1-3型压电单晶复合材料具有优异的压电性能和更匹配的声学特性, 更有利于制备出性能优异的超声换能器。该文通过有限元软件COMSOL对复合材料的振动模态及阻抗特性进行了系统的研究, 同时采用皮秒激光制备了高频1-3型Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3(PIN-PMN-PT)铁电单晶/环氧树脂复合材料,并进行了性能表征。该1-3复合材料机电耦合系数为0.65, 声阻抗为19.96 MRayls。该复合材料可用于制备高频超声换能器, 结果表明, 换能器中心频率为17.68 MHz, -6 dB带宽为84.38%, 插入损耗为-25.4 dB。

BiScO₃–PbTiO₃ binary ceramics own both high Curie temperature and prominent piezoelectric properties, while the high dielectric loss needs to be reduced substantially for practical application especially at high temperatures. In this work, a ternary perovskite system of (1–x–y)BiScO₃–yPbTiO₃–xBi(Mn2/3Sb1/3)O₃ (BS–yPT–xBMS) with x = 0.005, y = 0.630–0.645 and x = 0.015, y = 0.625–0.640 was prepared by the traditional solid-state reaction method. The phase structure, microstructure, dielectric/piezoelectric/ferroelectric properties were studied. Among BS–yPT–xBMS ceramic series, the BS–0.630PT–0.015BMS at morphotropic phase boundary possesses the reduced dielectric loss factor (tanδ = 1.20%) and increased mechanical quality factor (Qm = 84), and maintains a high Curie temperature ( TC = 410°C) and excellent piezoelectric properties (d33 = 330 pC/N) simultaneously. Of particular importance, at elevated temperature of 200°C, the value of tanδ is only increased to 1.59%. All these properties indicate that the BS–0.630PT–0.015BMS ceramic has great potential for application in high-temperature piezoelectric devices.BiScO₃–PbTiO₃ binary ceramics own both high Curie temperature and prominent piezoelectric properties, while the high dielectric loss needs to be reduced substantially for practical application especially at high temperatures. In this work, a ternary perovskite system of (1–x–y)BiScO₃–yPbTiO₃–xBi(Mn2/3Sb1/3)O₃ (BS–yPT–xBMS) with x = 0.005, y = 0.630–0.645 and x = 0.015, y = 0.625–0.640 was prepared by the traditional solid-state reaction method. The phase structure, microstructure, dielectric/piezoelectric/ferroelectric properties were studied. Among BS–yPT–xBMS ceramic series, the BS–0.630PT–0.015BMS at morphotropic phase boundary possesses the reduced dielectric loss factor (tanδ = 1.20%) and increased mechanical quality factor (Qm = 84), and maintains a high Curie temperature ( TC = 410°C) and excellent piezoelectric properties (d33 = 330 pC/N) simultaneously. Of particular importance, at elevated temperature of 200°C, the value of tanδ is only increased to 1.59%. All these properties indicate that the BS–0.630PT–0.015BMS ceramic has great potential for application in high-temperature piezoelectric devices.

针对高温超声检测技术的应用需求, 该文研究了基于钪酸铋-钛酸铅(BS-PT)基高温压电陶瓷材料的高温超声换能器。利用PiezoCAD器件仿真软件设计并制作了一款1 MHz的高温压电超声换能器, 且在200 ℃下对该器件的电学和声学性能进行了测试和分析。结果表明, 随着测试温度的升高, 换能器的脉冲回波幅值虽略有降低, 但其中心频率、带宽变化不明显, 带宽仍保持在20%左右。该文设计并制备的BS-PT基高温压电超声换能器可以在200 ℃环境中正常稳定工作。

压电微机械超声换能器(PMUT)在医疗阵列成像、手势识别、内窥成像、指纹识别等领域有着重要的应用, 而灵敏度等性能是影响其成像质量的主要因素。该文对基于PMN-PT圆形压电复合振动膜的压电微机械超声换能器等效电路模型进行分析, 并通过有限元法研究了压电层PMN-PT厚度对PMUT的发射电压响应、接收灵敏度的影响。仿真结果表明, 当压电层厚度为4.5 μm(厚度为基底厚度的90%)时, 换能器的发射电压响应级最大, 达到191.6 dB, 接收灵敏度级随厚度的增加基本呈线性上升趋势; 当压电层厚度为5.1 μm(厚度为基底厚度的102%)时, 回路增益(损耗)最大, 达到-64.50 dB。

折射率是光学晶体的基本参数，准确测定晶体的折射率能够为晶体的电光、声光、非线性应用提供基本计算参数和实验参量。为了准确测定Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN-PT)晶体在可见光和近红外波段的折射率系数，搭建了激光自准直折射率测量系统，对纯铌酸锂晶体的折射率测试结果与现有文献报道误差小于1/1 000，使用该系统对沿<001>极化的Pb(Mg1/3Nb2/3)O3-0.39PbTiO3(PMN-0.39PT)单畴晶体进行了测定，得到了单畴的PMN-0.39PT晶体在波长分别为594 nm、633 nm、1 150 nm和1 520 nm时的折射率和色散方程，测量结果与现有文献规律性一致。结果表明该方法可用于准确快速测定新型电光晶体折射率。

本文利用第一性原理方法计算并分析了体积应变(-11%~11%)对立方顺电相PbTiO3的结构、稳定性、电子结构和光学性质的影响。研究发现体积应变后PbTiO3形成焓增大，稳定性下降，其中压应变对其稳定性的影响比拉应变大。当受到拉伸应变时，立方PbTiO3由直接带隙半导体变为间接带隙半导体，且带隙随应变增大呈先增大后降低的趋势。在发生压应变时，从复介电函数、复折射率及吸收系数的分析结果可知，在自然光照下PbTiO3的光吸收能力仅在个别波段有所增大，但总体呈减弱趋势，当产生拉伸应变时，介电峰、吸收峰红移，表明PbTiO3在可见光范围内光吸收能力增强，并且当应变增大到11%时，PbTiO3的吸收能力远高于本征立方相。

根据对称金属包覆电光波导中本征损耗与古斯亨兴(Goos-Hnchen)位移的理论公式，导出了古斯亨兴位移与作用于波导两侧电压的二次关系公式。用622 μm厚度的四方相铌镁酸铅钛酸铅（PMN-PT）透明电光陶瓷片作为导波层制备了对称金属包覆波导，测量了古斯亨兴位移与作用于波导两侧电压的关系曲线，计算了所用透明电光陶瓷片的二次电光系数。实验结果与理论分析一致。

采用改进的Bridgman法生长出了大尺寸高质量的Pb(Mg1/3Nb2/3)O3-PbTiO3(PMNT)单晶,并发现了PMNT单晶具有非常大的热释电响应.为探索高性能的热释电材料,提高现有红外探测器的性能,对PMN-PT的热释电性能、及其在红外探测器中的应用进行了系统的研究.研究表明:PMNT单晶具有优异的热释电性能,其综合性能优于传统的热释电材料.用PMNT单晶制备出了的红外探测器.电压响应率和比探测率分别为Rv=211 V/W,D*=1.06×108 cm·Hz1/2·W-1,器件性能能够基本满足使用要求,同时也表明PMNT单晶有望在高性能的红外探测及成像器件中得到实际应用.