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本文简介了单晶材料的研究历史,发展过程.重点论述了近几年国内外单晶材料研究的实质性进展,特别是换能器应用的新成就.通过对驰豫型单晶材料的性能分析,期望在声纳换能器、医用超声换能器、成像技术、无损检验以及振动控制等技术应用领域不断有新的突破. 相似文献
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PMNT及其在水声换能器中的应用 总被引:3,自引:0,他引:3
本文阐述了弛豫铁电单晶PMN-PT、PZN-PT材料的性能特征及其在国内外水声领域应用的现状和发展趋势。并利用上海硅酸盐研究所提供的PMN-PT元件设计制作了单晶纵振换能器、厚度模换能器及加速度计。通过对PMNT换能器性能测试数据的分析,得到了一些较有意义的结论。 相似文献
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反铁电材料在发生场致反铁电-铁电相变过程中伴随着巨大应变和能量的储存和释放,故在高密度储能器件和机电换能器上极具应用潜力。综述了具有钙钛矿结构的Pb基反铁电体结构特点与性能调控,特别是Pb(Zr,Ti)O3(PZT)基反铁电储能材料的研究进展与存在问题。重点讨论了几类典型元素掺杂Pb基反铁电薄膜材料研究的最新进展。简要介绍了适应无铅化要求、环境友好的无铅钙钛矿型反铁电-铁电相变材料。最后对当前钙钛矿型Pb基反铁电材料研究与应用中尚需深入探究的问题进行了总结。 相似文献
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向广大科技工作者推荐一本既有原理的系统阐述又有广泛应用实例的专门著作──《超声换能器》。它几乎没有遗漏地包括了在该领域内我国科技工作者的各个研究方向。 本书强调超声换能器的基本理论,列出设计各种换能器所必需的大量公式、图解和表格。介绍了近年来国内外出现的换能器的新技术、新材料和新器件。论述了超声换能器的二维理论分析等难点问题 由于超声换能器的发展既涉及基础理论和工作材料的研究,也深入到诸如无损检测、生物医学诊断、地球物理勘探、水声、通信、信号处理以及与超声换能器有关的所有应用领域之中,因而本书… 相似文献
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Relaxor-PbTiO3 (PT) based ferroelectric crystals with the perovskite structure have been investigated over the last few decades due to their ultrahigh piezoelectric coefficients (d33 > 1500 pC/N) and electromechanical coupling factors (k33 > 90%), far outperforming state-of-the-art ferroelectric polycrystalline Pb(Zr,Ti)O3 ceramics, and are at the forefront of advanced electroacoustic applications. In this review, the performance merits of relaxor-PT crystals in various electroacoustic devices are presented from a piezoelectric material viewpoint. Opportunities come from not only the ultrahigh properties, specifically coupling and piezoelectric coefficients, but through novel vibration modes and crystallographic/domain engineering. Figure of merits (FOMs) of crystals with various compositions and phases were established for various applications, including medical ultrasonic transducers, underwater transducers, acoustic sensors and tweezers. For each device application, recent developments in relaxor-PT ferroelectric crystals were surveyed and compared with state-of-the-art polycrystalline piezoelectrics, with an emphasis on their strong anisotropic features and crystallographic uniqueness, including engineered domain–property relationships. This review starts with an introduction on electroacoustic transducers and the history of piezoelectric materials. The development of the high performance relaxor-PT single crystals, with a focus on their uniqueness in transducer applications, is then discussed. In the third part, various FOMs of piezoelectric materials for a wide range of ultrasound applications, including diagnostic ultrasound, therapeutic ultrasound, underwater acoustic and passive sensors, tactile sensors, acoustic tweezers and ultrasonic motors, are evaluated to provide a thorough understanding of the materials’ behavior under operational conditions. Structure–property–performance relationships are then established. Finally, the impacts and challenges of relaxor-PT crystals are summarized to guide on-going and future research in the development of relaxor-PT crystals for the next generation electroacoustic transducers. 相似文献
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新型弛豫铁电单晶材料铌铟酸铅-铌镁酸铅-钛酸铅晶体(Pb(In1/2Nb1/2) O3-Pb(Mg1/3Nb2/3) O3-PbTiO3, PIMNT)的压电系数是陶瓷材料的 6 倍以上,应变量高出压电陶瓷 10 倍以上,具有较高的机电耦合系数,压电性能优于传统 PZT 材料。文章将单晶材料应用于带空气腔的弯曲圆盘换能器中,利用 ANSYS 仿真软件优化换能器结构,确定换能器尺寸,设计制作 PIMNT 压电单晶换能器和PZT4压电陶瓷换能器,并进行了水池实验。换能器实测结果与仿真结果保持一致,单晶换能器的谐振频率为 2.85 kHz,最大发送电压响应为 136.3 dB。结果表明,相比于同尺寸的陶瓷换能器,将 PIMNT 压电单晶应用于弯曲圆盘换能器可降低谐振频率,提高发送电压响应,提升换能器的工作性能,为进一步改善单晶换能器综合性能提供参考。 相似文献
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光电功能晶体,包括激光晶体、非线性光学晶体、电光晶体、介电体超晶格、闪烁晶体和PMN-PT驰豫电单晶等,在高技术发展中具有不可替代的重要作用。近年来,我国在这些重要晶体材料的生长、基础研究和应用方面都获得了很大成绩。综述了光电功能晶体材料研究和应用的部分进展。在此基础上,提出进一步发展晶体理论,扩大理论的应用范围,注重晶体生长基本理论研究,发展新的晶体生长方法和技术,加强晶体生长设备研制,加强晶体从原料到加工、后处理、检测及镀膜等全过程的结合等建议,以全面提高我国光电功能晶体研究发展及其产业化水平。 相似文献
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高频超声成像以其高分辨和实时性好等优势成为近年来医学超声成像领域研究的热点。但由于超声的衰减随频率增加呈指数级升高,导致高频超声信号幅值小,图像信噪比低。为了增强高频超声成像的信噪比,近年来编码发射(又称编码激励)技术得到了越来越多的研究和应用。文章对近几年国内外编码发射技术在医学高频超声成像方面的应用和研究进展进行了综述,重点分析了Chirp码、巴克(Barker)码和格雷(Golay)码3种主要编码发射技术在高频超声成像方面应用的优缺点,并综合对比了各种编码发射技术在高频成像方面的应用前景。 相似文献
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An experimental procedure adopted to prepare the recent ferroelectric glycine phosphite single crystals is presented. As the crystal solubility in water depends on temperature, single crystals were grown from fine seed crystals in a saturated solution by employing the slow cooling technique. Transparent, colourless crystals with habit morphology weighing about 8 g were obtained within a month. The same procedure was used to grow single crystals with urea (UGPI). Powder X-ray diffraction studies as well as FTIR studies were carried out on both the crystals. The thermal properties of glycine phosphite (GPI) and UGPI across the ferroelectric phase transition temperature has been carried out. The results will be discussed in detail. 相似文献
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目的 综述国内外非晶光子晶体结构呈色的研究进展,为进一步研究非晶光子晶体在印刷颜料、光学防伪、功能性包装材料以及彩色显示器、传感器等领域的应用提供理论依据。方法 概括非晶光子晶体的概念、材料的选取与制备方法以及国内外的研究进展,分析该类材料在应用过程中存在的问题,并总结目前非晶光子晶体研究所面临的挑战和未来的发展方向。结论 非晶光子晶体具有非虹彩效应、各向同性、光局域化等特点,为包装印刷等相关领域的研究及应用提供了新思路、新方法,有望早日将这一绿色环保、经济高效型的材料实现规模化应用。 相似文献
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Piezoelectric films have recently attracted considerable attention in the development of various sensor and actuator devices such as nonvolatile memories, tunable microwave circuits and ultrasound transducers. In this paper, an overview of the state of art in piezoelectric films for high frequency transducer applications is presented. Firstly, the basic principles of piezoelectric materials and design considerations for ultrasound transducers will be introduced. Following the review, the current status of the piezoelectric films and recent progress in the development of high frequency ultrasonic transducers will be discussed. Then details for preparation and structure of the materials derived from piezoelectric thick film technologies will be described. Both chemical and physical methods are included in the discussion, namely, the sol-gel approach, aerosol technology and hydrothermal method. The electric and piezoelectric properties of the piezoelectric films, which are very important for transducer applications, such as permittivity and electromechanical coupling factor, are also addressed. Finally, the recent developments in the high frequency transducers and arrays with piezoelectric ZnO and PZT thick film using MEMS technology are presented. In addition, current problems and further direction of the piezoelectric films for very high frequency ultrasound application (up to GHz) are also discussed. 相似文献
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弛豫型铁电体PZNT制备与性能研究的进展 总被引:4,自引:0,他引:4
本文综述了近年来国际上弛豫型铁电体PZNT的制备与介电、压电及电致伸缩性能研究的进展.PZNT单晶体的制备方法以高温PbO熔剂法为主,其尺寸已达40mm.随PT含量的变化,PZNT的顺电一铁电相交由弥散性、混合型变为一级相变;其铁电-铁电相变可由组份或电场诱导,由介电性能表征.压电性能在MPB处及偏向三方相一侧达到最佳,<001>切向的三方相与四方相单晶可分别作为频带宽、分辨率高、且阻抗匹配好的新一代声阵列与单个器件传感器.<001>向的PZNT单晶具有巨大的电致伸缩应变,可望成为高性能的固体驱动器. 相似文献