铁电材料Bi4Ti3O12及应用

叙述了Ｂｉ４Ｔｉ３Ｏ１２材料的结构、性质和制备方法，并对Ｂｉ４Ｔｉ３Ｏ１２铁电薄膜的研究现状和应用前景作了简单分析。     

我国铁电液晶材料研究进展

自从Clark与Lagerwall提出表面双稳铁电液晶显示原理后，铁电液晶材料在显示领域中的应用一直是国内外研究的热点课题，总结了国内外近年来铁电液晶材料的合成与研究工作和目前在显示领域应用中遇到的问题，并阐述了在其他领域的应用前景。     

铁电技术

铁电材料具有良好的铁电、光电及压电特性,可用以制作非易失性存诸器、光集成器件等,在空间、军事及其它民用领域均有美好的应用前景。     

半导体温差电材料及其致冷器

用改良的布里奇曼法制备以碲化铋(Bi_2Te_3)为基并掺入适量中性杂质元素的室温半导体温差电材料,晶体直径为φ19—25mm,其特性具有明显的取向性,平行于晶锭轴切取电偶臂时比垂直切取具有更好的性能。优值系数p型Z达3.2×10~(-3)K~(-1),n型Z达3.1×10~(-1)K~(-1)。文中还介绍了致冷器的工作原理、设计的基本依据和主要的计算公式,以及制作致冷器的主要工艺步骤。     

铁电薄膜材料及其制备技术的发展

综述了铁电薄膜材料及铁电薄膜制备技术的发展概况。阐述了几种典型铁电薄膜材料及主要制备技术的特点。     

当前铁电学和铁电材料研究的几个问题

概括分析了近一二年来国际上铁电学和铁电材料研究的发展，提出了发展我国相关研究的一些设想，包括铁电物理学的发展、铁电材料的研究、铁电薄膜、铁电薄膜器件的市场前景分析，以及铁电微电机械系统等．     

爆电换能用反铁电材料

采用爆炸冲击波作用于贮存有电极化能量的铁电体，迫使其转变成反铁电体，可释放出巨大电能量，用于一次性的高压、大功率脉冲电源。本工作研究了锆钛酸铅反铁电材料在电场、压力、温度作用下的反铁电一铁电相变性质，介绍了在爆炸冲击波作用下铁电向反铁电转变过程中电量的输出特性。     

铁电材料的开关电流测试系统

铁电材料极化后,如果把前沿很陡的矩形电压脉冲加到铁电材料上,在铁电畴反转过程中将产生不同于充电电流的开关电流。利用微机、控制、数字示波器及自制测试仪器研制成了一套铁电材料开关电流测试系统。     

新型MEMS微致冷器可行性研究

MEMS的高能量密度驱动和IC高度集成使MEMS器件严生较强的热效应,影响了MEMS器件的稳定性和寿命。传统的致冷器与待致冷器件是相对独立的器件,无法满足MEMS器件局部有效致冷和系统集成的要求。介绍了一种新型铁电薄／厚膜MEMS微致冷器的原理和设计,探讨其作为MEMS致冷器的可行性,该致冷器可以在较大工作温度范围内,对基于IC硅工艺的MEMS器件和普通IC芯片进行致冷。     

压电和铁电薄膜及其应用的发展趋势

本文讨论了压电和铁电薄膜材料及其在固体器件中应用的发展趋势。薄膜生长技术的进展,为压电和铁电薄膜集成固体器件在各个领域的应用开辟了广阔的前景。ZnO和AIN薄膜将广泛地用于SAW和BAW器件。特别是成功地制作了薄膜体声波谐振器和高次谐波体波谐振器。以PbTiO_3为基的PZT和PLZT固溶体外延薄膜将应用于热电探测器和SAW器件。在实现了对多层薄膜的界面结构及其特性的成功控制之后,铁电薄膜将在铁电存储和集成光学领域发挥重要作用。     

钛酸铅系铁电光伏材料研究进展

铁电材料由于具有反常光生伏打效应,使其在光传感器、光驱动器、铁电光伏电池等领域具有重要的应用前景。钛酸铅系铁电材料具有大的自发极化强度,成为研究热点。文章介绍了铁电材料反常光生伏打效应的原理及钛酸铅系铁电光伏材料的研究进展,提出了研究中需要解决的一些问题。     

微型MEMS致冷器的研究新动向

微机电系统(MEMS)与超大规模集成电路(ULIC)进一步微型化与集成化,急需微型冷却系统对其芯片等进行局部冷却。因此,基于硅微机械加工工艺的微型致冷器被提上研究日程,并有望发展成为无压缩机、无机械部件的新型致冷器。着重介绍了微型MEMS致冷器的国内外研究动向与发展趋势,阐述并分析了几种典型致冷材料与器件的工作原理、技术可行性及应用研究前景。     

Ferroelectric Properties and Applications of Hybrid Organic-Inorganic Perovskites

Hybrid organic-inorganic perovskites (e.g. CH3NH3PbI3) have attracted tremendous attention due to their promise for achieving next-generation cost-effective and high performance optoelectronic devices. These hybrid organic-inorganic perovskites possess excellent optical and electronic properties, including strong light absorption, high carrier abilities, optimized charge diffusion lengths, and reduced charge recombination etc., leading to their widespread applications in advanced solar energy technologies (e.g. high efficiency perovskite solar cells). However, there is still a lack of investigations regarding fundamental properties such as ferroelectricity in these perovskites. As conventional ferroelectric ceramics are prepared at high temperature and have no mechanically flexibility, low-temperature proceed and flexible perovskite ferroelectrics have become promising candidates and should be exploited for future flexible ferroelectric applications. Here, ferroelectric properties in hybrid organic-inorganic perovskites and several state-of-the-art perovskite ferroelectrics are reviewed. Novel ferroelectric applications of hybrid organic-inorganic perovskites are discussed as well, providing guideline for realizing future high performance and flexible ferroelectric devices.     

显微结构对BaTiO3陶瓷电热性能的影响

该文研究了显微结构对BaTiO3陶瓷电热特性与击穿电场的影响.采用固相反应法制备BaTiO3粉体,经干压结合冷等静压工艺成型后,在不同温度下烧结成陶瓷样品.随烧结温度提高,陶瓷晶粒长大、结构更致密,由此导致极化强度与电热效应绝热变温明显提高,但击穿电场下降.等静压工艺可进一步提升瓷体致密度并促进晶粒长大,使电热效应提升.     

Observation of a Negative Thermal Hysteresis in Relaxor Ferroelectric Polymers

Hysteresis phenomena, including both electrical and thermal types, are essential to ferroelectric materials. The former, known as polarization‐electric field hysteresis, has been intensively studied in a wide range of ferroelectric materials. However, relevant experimental evidence on thermal hysteresis remains limited, especially in ferroelectric polymers, even though thermal hysteresis is crucial to the caloric effect, which is usually the largest near the phase transition. Here, the thermal hysteresis behavior in ferroelectric polymers is studied in terms of temperature‐dependent polarization upon heating and cooling. In contrast to common belief, a negative thermal hysteresis is observed in relaxor ferroelectric polymers, which is probably due to local stabilization of ferroelectric distortion induced by electric field. Using the polymer blend as a platform, it is further shown that the negative thermal hysteresis arises at the disappearance of long‐range ferroelectric distortion and the thermal hysteresis behavior may be effectively controlled through the blend approach. This study not only provides deeper insights into electrocaloric effect in ferroelectric polymers but also offers an approach to study the critical phenomenon in a ferroelectric system.     

Scavenging Energy Sources Using Ferroelectric Materials

Ferroelectric materials have attracted interest for over a hundred years as a result of their spontaneous polarization and a polarization orientation that can be reversed by the application of an external electric field. In addition, the degree of polarization can be affected by external stimuli such as vibrations, stress, heat, and light. These properties enable ferroelectric materials to be used to fabricate nanogenerators, which are devices used in energy scavenging applications and provide an opportunity to obtain electrical energy from a variety of external stimuli. This review discusses the development of ferroelectric-based nanogenerators for scavenging mechanical, thermal, and solar energies through the piezoelectric effect, pyroelectric effect, and photovoltaic effect, respectively. The mechanisms of the effects and the pathways to optimize the output performance of the nanogenerators are analyzed in detail. Recent developments in energy harvesting using ferroelectric materials are discussed with the objective to motivate attention and efforts in this growing field.     

MEMS器件中的铁电材料

铁电材料在微电子技术、光电子技术和集成光学等多个领域中具有极为重要的应用价值。本文简要介绍了铁电材料及其在MEMS器件方面的应用情况。