微波-水热法制备无铅压电陶瓷粉体

综述了微波-水热法合成无铅压电陶瓷粉体的优越性,指出了无铅压电陶瓷制备工艺的重要性.介绍了无铅压电陶瓷粉体的制备方法及其优缺点和微波-水热法合成粉体的由来,阐述了微波-水热法合成无铅压电陶瓷粉体的作用原理、微波液相合成技术的特点和微波-水热法制备无铅压电陶瓷粉体的工艺参数.探讨了微波-水热法制备无铅压电陶瓷粉体对陶瓷性能的影响,同时,提出了该新路线有待解决的问题并展望了该领域未来的发展方向.     

氧化锌压敏陶瓷粉体的研究进展

综述了氧化锌压敏陶瓷粉体的研究进展,分析了粉体特性对压敏电阻微观结构和电性能的影响以及粉体制备中存在的问题.对粉体的制备方法和应用前景进行了展望,指出化学法合成复合粉体和高能球磨法制备纳米粉体是氧化锌压敏陶瓷粉体的两个主要发展趋势.     

水热法在制备电子陶瓷粉体中的应用

近年来,水热法用于纳米粉体和纳米材料制备,超导材料处理等前沿课题的研究,已引起人们的高度重视,按研究对象和目的的不同,水热法可分为水热晶体生长,水热合成,水热反应,水热处理,水热燃结等,分别用来生长各种单晶,制备超细,无团聚或少团聚,结晶完好的陶瓷粉体,以及在相对较低的温度下完成某些陶瓷材料的合成等,对水热技术的原理和发展,以及该技术在电子陶瓷粉体制备中的应用进行了介绍。     

沉积法制备TaN薄膜的研究现状及其应用

TaN薄膜是一种重要的高新技术材料,主要介绍了物理气相沉积法(PVD)、金属有机化学气相沉积法(MOCVD)和原子层沉积法(ALD)制备TaN薄膜的工艺技术,评述了它们各自的优缺点.从前驱体的选择方面详细评述了MOCVD法和ALD法制备TaN薄膜的研究进展,比较和评述了各类前驱体的优缺点.总结了TaN薄膜的应用现状以及薄膜制备过程中的主要影响因素,并简要展望了其发展方向.     

项目推荐

本项目以溶胶-凝胶燃烧合成技术为基础,进行单相和复合钛酸钡基纳米电子陶瓷粉体的低成本制备。铁电陶瓷粉体及其集成器件的研究与开发是目前最为活跃的领域之一。其中最为重要的是BaTiO3基氧化物陶瓷粉体及其器件。由于其具有优越的介电、压电、铁电性能,被广泛应用于制备各种陶瓷电容器、微波器件、铁电存储器等电子器件。近二十多年来,用BaTiO3研制的PTCR广泛应用于工业电子设备,民用电子设备和电器部件。BaTiO3基陶瓷的各种性能受很多方面的影响,其中钛酸钡陶瓷粉体的质量就是其中最为关键的一个方面。随着现代科学技术的飞速发展和电子元件的小型化、高度集成化,需要制备与合成符合发展要求的高质量的钛酸钡基陶瓷粉体（纳米颗粒、超纯、单分散、分子与原子水平上的成分复合）。纳米BaTiO3电子陶瓷     

水热合成无铅压电陶瓷粉体

简述了水热法在国内外的发展现状,重点介绍了目前水热法制备BaTiO3、(K1-xNax)NbO3、Na0.5Bi0.5-TiO3以及Bi4Ti3O12等4种无铅压电陶瓷粉体的工艺过程,及其在制备4种粉体过程中对粉体尺寸、形貌的控制和独特的优势,同时简要评述了近年来微波水热法制备无铅压电陶瓷粉体的新工艺进展,指出水热法在制备无铅压电陶瓷方面具有一定的优势,可以制备出纯度和结晶性高、颗粒分布均匀、尺寸和形貌可控的高性能简单化合物无铅压电陶瓷粉体。下一步研究的重点和难点为合成组分可控的复杂化合物,为真正实现压电陶瓷和器件的无铅化革命作贡献。     

利用无机盐制备γ-Al2O3粉体与薄膜的工艺技术研究

发明了γ-A12O3基陶瓷气敏传感器材料体系,并正研究其薄膜型传感器件.本文以廉价的无机盐Al(NO3)3·9H2O为原料,通过溶胶-凝胶法制备了勃姆石(γ-A1OOH)溶胶,然后经干燥、煅烧制备了γ-Al2O3的粉体,并通过旋转涂覆工艺制备了γ-A12O3的薄膜,应用X射线衍射(XRD)、X射线光电子能谱(XPS)、原子力显微镜(AFM)等现代分析技术对粉体的物相和薄膜的组分及表面形貌进行了表征,对γ-A1OOH溶胶制备过程中的一些影响因素进行了探讨,得出了比较好的制备γ-Al2O3基陶瓷粉体和薄膜型气敏传感器的工艺技术条件.     

脉冲激光沉积法制备VO_2热致变色薄膜研究进展

基于半导体和金属间的相变特性,伴随着温度、电场、压力的变化,具有相关智能特性的VO_2薄膜材料具有较大的应用潜力.本文主要阐述脉冲激光沉积技术在制备金属氧化物方面的物理过程和技术特点,详细介绍脉冲激光沉积制备VO_2薄膜材料的工艺参数和国内外研究进展,并与几种常规制备方法进行对比,给出脉冲激光沉积掺杂对VO_2薄膜材料特性的影响,以及采用脉冲激光沉积制备VO_2纳米材料,讨论了脉冲激光沉积制备具有智能特性的VO_2薄膜材料存在的问题和发展方向.     

水性聚合物网络凝胶法制备纳米镁铝尖晶石粉末

用水性聚合物网络凝胶法制备了纳米镁铝尖晶石陶瓷粉体,研究了镁铝尖晶石陶瓷粉体的制备工艺过程.研究结果表明:通过网络的阻碍作用,阻止了陶瓷粉体的团聚,获得了颗粒大小在50nm左右的镁铝尖晶石陶瓷粉体,其煅烧温度比通常低100℃.     

钽酸锂薄膜材料及其热释电红外传感器应用研究进展

介绍了钽酸锂薄膜材料及其热释电红外传感器应用研究概况;简要阐述了热释电红外传感器的工作原理;着重分析了钽酸锂薄膜材料的新制备技术,以及在热释电红外传感器应用方面的研究现状;指出了钽酸锂薄膜材料及其热释电红外传感器应用研究发展前景.     

Electrical properties of ZnO/Au/ZnS/Au films deposited by ultrasonic spray pyrolysis

Polycrystalline ZnS semiconducting films have been prepared by ultrasonic spray pyrolysis technique in the form of planar and sandwich configurations using amorphous and ZnO coated glass substrates. Deposition of ZnS films by the spray pyrolysis has been studied extensively by several investigators and the process parameters have been optimized to obtain films with good characteristics. However we report for the first time the preparation of ZnS films sandwiched between top and bottom electrodes on the transparent conducting ZnO films that have been produced by the spray pyrolysis technique. The produced ZnS films have been crystallized in a wurtzite structure. The electrical properties of the samples having planar and sandwich structures have been measured in dark at room temperature by applying the voltage values between 0.01 and 100 V.     

Studies on dynamicI-V curves of semiconductor-liquid junction cells formed with Cd0·8Zn0·2S films prepared at various spray rates

Cd_0·8Zn_0·2S films were prepared by the spray pyrolysis technique on glass and conducting glass (fluorine doped tin oxide) substrates, by spraying aqueous solutions of cadmium chloride, zinc chloride and thiourea. The spray rate was varied from 4 cc/min to 16 cc/min. It is found that film thickness increases with increase in spray rate. The electrical and optical properties of the films namely dark conductivity, thermoelectric power and optical absorption were studied; conductivity and thermoelectric power are higher for the films prepared at lower spray rate (4·3 cc/min).     

Investigation on the effect of NiO content on spray deposited ZnO for selective ammonia detection

Journal of Materials Science: Materials in Electronics - Zinc Oxide/Nickel Oxide (ZnO/NiO) heterostructures were deposited using the spray pyrolysis technique by varying NiO content. The X-ray...     

Spray pyrolysis deposition of polycrystalline magnesia films and their use as buffer layers in Bi(Pb)-Sr-Ca-Cu-O/MgO/Al2O3 (or glass ceramics) structures

The deposition of MgO films on Al₂O₃ and glass ceramic substrates by spray pyrolysis of a water-ethanol magnesium nitrate precursor solution has been studied. Dense polycrystalline films have been obtained by repeated pyrolysis at 300–350 °C followed by annealing of the deposit in air at 970 °C. It has been established that the finest grains obtained under these experimental conditions correspond to the films deposited on glass ceramic substrates. It has been shown that the MgO films can be useful buffer layers preventing the interaction between the above substrates and the BiSr-Ca-Cu-O films deposited on them by spray pyrolysis of nitrates.     

Direct synthesis of strontium titanate phosphor particles with high luminescence by flame spray pyrolysis

SrTiO₃:Pr, Al phosphor particles with high luminescence intensities were directly prepared by flame spray pyrolysis without post-treatment. They had better crystallinity than those prepared by general spray pyrolysis with post-treatment and solid-state reaction methods. In addition, they had complete spherical shape and narrow size distribution. On the other hand, the particles prepared by general spray pyrolysis had irregular shape, and poorer brightness than those prepared by solid-state reaction method, while the particles prepared by flame spray pyrolysis had comparable photoluminescence and cathodoluminescence intensities with those of particles prepared by solid-state reaction method. The photoluminescence intensity of SrTiO₃:Pr, Al particles prepared by flame spray pyrolysis was as much as 4.7 times higher than that of particles prepared by general spray pyrolysis.     

Aqueous synthesis of interconnected ZnO nanowires using spray pyrolysis deposited seed layers

Interconnected ZnO nanowires were grown in a two-stage process, using spray pyrolysis deposited ZnO seed layers as a nucleation platform for subsequent hydrothermal growth. We present a comparison between the effect of these spray pyrolysis deposited seed layers and well-ordered sputter deposited seed layers, along with their respective ZnO nano-morphologies that were obtained via hydrothermal growth. It will be shown that the growth of interconnected ZnO nanowires was influenced by the physical and crystallographic orientations of the underlying seed crystallites. Sputtered seed layers resulted in fairly vertical nanorods which were approximately 80 nm in width, while seed layers deposited by spray pyrolysis resulted in arrays of interconnected ZnO nanowires measuring approximately 15 nm in width.     

Impact of yttrium on structural,optical and electrical behavior of CuO thin film prepared by JN spray pyrolysis technique for diode application

Journal of Materials Science: Materials in Electronics - The thin films of CuO with yttrium as a dopant at 1, 3, and 5wt% are prepared using a simple and economic JNS spray pyrolysis technique at...     

The electrical and dielectric characterization of the Co/ZnO-Rods/p-Si heterostructure depending on the frequency

Journal of Materials Science: Materials in Electronics - Zinc oxide (ZnO) rods film was fabricated by homemade and simple spray pyrolysis technique on a p-type silicon (Si) substrate, and the film...     

Effect of pyrolysis temperature on structural,microstructural and optical properties of nanocrystalline ZnO powders synthesised by ultrasonic spray pyrolysis technique

In this article, we report on the effect of pyrolysis temperature on structural, microstructural and optical properties of nanocrystalline ZnO powder synthesised by ultrasonic spray pyrolysis (USP) technique. Powder samples P1, P2 and P3 were prepared at various pyrolysis temperatures (temperature of 2nd zone) of 973, 1073 and 1273?K, respectively. Phases were identified and crystallite sizes were calculated from X-ray diffraction (XRD) diagrams. The morphology and size of ZnO nanocrystallites associated with nanopowder were studied using transmission electron micrograph (TEM). It revealed that the powder consisted of crystallites ranging in size from 9 to 20?nm. These values were matching with the crystallite sizes calculated from XRD. Both XRD and TEM studies of ZnO nanopowders showed that the crystallite sizes increased with an increase in the pyrolysis temperature. The synthesised nanopowders exhibited direct band gap (E _g) in the range 3.37–3.40?eV.