水热法制备薄膜材料技术研究进展

水热法制备薄膜是近年来发展起来的一种很有潜力的液相制膜技术，在制备压电、铁电和氧化物薄膜等领域内的研究很活跃。笔者介绍了水热法制备薄膜技术的发展、原理、特点以及在材料研究中的应用和发展前景等，综述了相关的研究成果。     

水热法制备陶瓷粉体的机理与应用

水热法是重要的陶瓷粉体制备方法之一。本文详细介绍了水热法制备陶瓷粉体的多种方法;讨论了水热法制备陶瓷粉体的机理;分析了此法制备陶瓷粉体的特点,并对今后的应用与发展作了展望。     

氧化物纳米管的水热法制备及其形成机理

结合国内外研究现状论述了氧化物纳米管的用途,介绍了制备氧化物纳米管的方法,详细讨论了水热法制备纳米管的影响因素以及氧化物纳米管的形成机理.     

低温水热法制备纳米氧化锆粉体

本文以ZrOC12为原料、NH3·H2O为沉淀剂、CaC12为稳定剂,采用交叉喷淋法制备氧化锆前驱体,通过改变反应釜内前驱体浓度、矿化剂NaOH的加入及矿化剂NaOH浓度,采用低温水热法制备纳米氧化锆粉体.结果表明:反应釜内前驱体浓度降低有利于提高粉体的结晶度,矿化剂NaOH的加入可有效降低水热反应温度.当反应温度为110℃、保温时间2h、反应釜内前驱体的浓度为0.25 mol/L、矿化剂NaOH浓度为1 mol/L时,可制备平均粒径为26 nm的四方相氧化锆粉体.     

水热法制备纳米陶瓷粉体技术

文章较为系统地概述了水热法制备纳米陶瓷粉体的技术方法、特点和研究进展。认为水热法是一种极有应用前景的纳米陶瓷粉体的制备方法.     

水热法制备氧化锰纳米材料及其电容性能

基于KMnO4的自分解反应,采用水热法在180℃制备了氧化锰材料.应用X-射线衍射、扫描电镜和透射电镜技术对所得材料的结构和形貌进行了表征.结果表明,所得材料为具有Birnessite结构的层状氧化锰花球,花球由纳米片组装而成.电化学测试结果显示,制备材料表现出优良的电容特性.当电流密度为0.25 A/g时,比电容为173 F/g.在10 mV/s的扫描速度下,循环测试1000圈后比电容保持率高达97％.     

水热法制备BiFeO3粉体的工艺研究

以Bi(NO)3·5H2O和Fe(NO)3·9H2O为初始原料,KOH、NaOH和LiOH·H2O为矿化剂,乙二醇、浓度为65％ ～68％硝酸和氨水为辅助试剂,水热合成BiFeO3粉体.X-射线衍射图表明,当采用不同的矿化剂合成样品时,可以得到不同的铋铁系化合物,采用KOH为矿化剂时,更容易得到单相BiFeO3粉体;另外发现不使用辅助剂溶解硝酸铋,不仅容易得到单相BiFeO3粉体样品,而且工艺简单.在此基础上,进一步研究了KOH浓度、反应时间、反应温度和前驱物浓度对合成单相BiFeO3粉体的影响.     

一步水热法制备石墨烯透明分散体及其应用

通过一步水热法成功制备出透明石墨烯分散体,并采用TEM、XRD、UV-Vis、FTIR、Raman和XPS等手段对所得分散体中的石墨烯进行了详细的结构表征.所制备的分散体稳定性好,可以在室温下稳定保存超过0.5 a.该分散体通过真空抽滤法制备了石墨烯透明导电薄膜,在可见光透过率为85.3％时,薄膜电阻为1.62 kΩ/...     

高纯天然石膏水热法制备硫酸钙晶须研究

以高纯天然石膏为原料，加压水热法制备高品质硫酸钙晶须。采用常规分析方法、XRD和扫描电镜等手段分析和表征石膏原料和硫酸钙晶须产品。结果表明，制备硫酸钙晶须的最优条件为：料浆质量分数为6.0%，转晶剂氯化镁加入量为石膏质量的0.05%，硫酸加入量为水体积的1.0%，反应时间为4.0 h，快速过滤干燥即得硫酸钙晶须产品。分析结果表明：硫酸钙晶须长度最大为280.4 μm，最小为19.59 μm，平均长度为80 μm；硫酸钙晶须直径最大为5.86 μm，最小为0.20 μm，平均直径为2.67 μm；通过统计分析可知，长径比范围为10～80。     

水热法制备球形二氧化锆粉体的研究

以氯氧锫为前躯体通过水热法制备出了粒径在5μm左右,粒度分布均匀的球形二氧化锆粉体.研究结果表明水热温度、水热时间以及醇水比例对产物的微观结构均有影响.140℃水热处理24h获得产物为无定型态的氢氧化锆粉体,而200℃水热处理24h可获得单斜和四方混相的二氧化锆粉体.随水热时间的延长,产物相结构经历了由无定型氢氧化锆向单斜与四方混相的二氧化锆转变,相转变机制则经历了由均匀饱和析出机制到溶解沉淀为主、原位结晶为辅机制再到原位结晶为主、溶解沉淀为辅机制的变化过程.     

LBL技术制备有机/无机纳米复合薄膜研究进展

将高分子和各种功能的无机纳米粒子通过层层吸附自组装技术进行组装,制备厚度可控和稳定性好的有机/无机纳米复合薄膜。综述了该领域研究的最新进展,介绍了利用LBL技术制备有机/无机纳米复合薄膜的方法,并对利用LBL技术制备有机/无机纳米复合薄膜的发展趋势作了展望。     

水热电耦合法制备BaZrO_3薄膜

本研究采用水热电耦合方法合成了BaZrO3薄膜。首先通过阴极放电等离子体(HCD-IP)在Si基片上沉积氮化锆(ZrN)薄膜,接着将包覆ZrN的Si基片侵入到水热电耦合装置中,其混合溶液为Ba(CH3COO)2和NaOH,在90℃的温度下工作1～15h。结果表明,在ZrN/Si基片上成功合成了立方BaZrO3薄膜。BaZrO3薄膜在ZrN上的生长速率比在块体Zr上的生长速率快,BaZrO3薄膜展示出纳米层结构,其厚度在15h后可达到2μm。本文讨论了溶液的反应温度和反应时间对薄膜形貌和厚度的影响。     

水热合成法制备ZnO纳米棒有序阵列薄膜

采用水热合成法在预先生长的ZnO种子层的玻璃衬底上制备出ZnO纳米棒有序阵列薄膜。通过X射线衍射、扫描电镜、透射电镜和选区电子衍射分析表明：所制备的薄膜由垂直于ZnO种子层的纳米棒组成,呈单晶六角纤锌矿ZnO结构,且沿[001]方向择优生长,纳米棒的平均直径和长度分别为10．0nm和3．3μm。     

Hydrothermal Synthesis of Thin Films of Barium Titanate Ceramic Nano-Tubes at 200°C

A novel, low-temperature synthesis method for producing BaTiO₃ thin films patterned in the form of nano-tubes ("honeycomb") on Ti substrates is reported. In this two-step method, the Ti substrate is first anodized to produce a surface layer (∼200–300-nm thickness) of amorphous titanium oxide nano-tube (∼100-nm diameter) arrays. In the second step, the anodized substrate is subjected to hydrothermal treatment in aqueous Ba(OH)₂, where the nano-tube arrays serve as templates for their hydrothermal conversion to polycrystalline BaTiO₃ nano-tubes. This opens the possibility of tailoring the nano-tube arrays and of using various precursor solutions and their combinations in the hydrothermal bath, to produce ordered, patterned thin-film structures of various Ti-containing ceramics. These could find use not only in a variety of electronic device applications but also in biomedical applications, where patterned thin films are also desirable.     

Microstructure Development in Unsupported Thin Films

To better understand the role of the substrate in the microstructural evolution of thin films, unsupported nanocrystalline yttrium-stabilized zirconia (ZrO₂:16%Y or YSZ) films were examined as a function of temperature and annealing time. Grain growth, texturing, and pinhole formation were measured using transmission electron microscopy (TEM) and electron diffraction. Films were produced and subsequently annealed on metallic grids using a previously developed technique that results in near full density films at low annealing temperatures. Microstructural evolution in these films was unique compared with constrained films. Grains were found to spheroidize much more readily, ultimately resulting in the formation of porosity and pinholes. Grain growth was found to stagnate at a size particular to each annealing temperature, presumably due to the effects of Zener pinning. It is proposed that the lack of substrate strain and confinement effects allows for the dominance of surface energetics with respect to microstructural evolution.     

Preparation of Tetragonal Barium Titanate Thin Film on Titanium Metal Substrate by Hydrothermal Method

Tetragonal BaTiO₃ thin films were prepared directly on Ti metal substrates in Ba(OH)₂ solutions by a hydrothermal method at temperatures 400° to 800°C for 5 to 240 min. The film thickness estimated from weight gain of Ti plate was in the range from 0.5 to 2.5 μm, and it increased with increasing treatment temperature, treatment time, and Ba(OH)₂ concentration. Rectangular crystals having {100} and {001} faces grew idiomorphically with approximate crystal size of 0.3 to 2.0 μm. The tetragonality of the BaTiO₃ films became apparent when the average crystal size exceeded about 1 μm. Lattice parameters of the films were a = 3.994 Å, c = 4.035 Å, and c/a = 1.010. The films formed above 600°C had preferred orientation showing stronger XRD peaks of h 00 and 00 l than the other peaks.     

Platinum-Containing Diamond-like Carbon Thin Films

This paper reports a composite thin film of platinum–diamond-like carbon (Pt-DLC). "Nonreactive" and reactive rf sputter deposition techniques were used for the preparation of these thin films under various ratios of Ar/CH₄. As-deposited thin films were characterized for microstructures using transmission electron microscopy and Raman spectroscopy, compositions using electron probe for microanalysis, surface morphology using scanning electron microscopy, and sheet resistance using four-point probe. Correlations among the growth parameter, film composition, and structure are presented. Such correlations were found to depend on the deposition technique. Improved electrical conductivity and reduced film stress were also found due to the addition of platinum to DLC.     

ITO薄膜的研究进展

ITO是锡掺杂氧化铟薄膜的简称,属于透明导电氧化物材料。常规沉积方法制备的ITO薄膜通常为非晶态或体心立方晶系晶体,为n型半导体材料,其载流子为自由电子,主要来源于沉积过程中薄膜化学计量比偏离或阳离子掺杂形成的施主杂质。ITO薄膜是当前研究和使用最为广泛的透明导电氧化物薄膜材料,由于具有低电阻率、高可见光透过率、高红外反射率等独特物理特性而被大量应用于平板显示器、太阳能电池、发光二极管、气体传感器、飞机风挡玻璃除霜器等领域。此外,ITO薄膜对微波还具有高达85%的衰减作用,因而在电磁屏蔽等军用领域显示出巨大的潜在应用价值。过去几十年里,针对ITO薄膜的研究工作主要聚焦于薄膜的光电性能上。当前,伴随着ITO薄膜的应用范围在航空航天和军用武器装备等领域的拓展,ITO薄膜在恶劣力学环境中的使用日渐增多。因此,除光电性能外,ITO薄膜的力学性能也开始受到研究者越来越多的关注,人们对薄膜器件在各类恶劣使用环境中的稳定性及耐久性提出了更高的要求,这一要求使得对ITO薄膜力学性能的深入研究分析有了重要的理论及实际意义。本文综述了近年来ITO薄膜在微结构特性、能带结构、光电性能及力学性能等方面的研究进展,简略探讨了ITO薄膜的研究发展方向。     

SrBi_2Ta_2O_9薄膜的制备和铁电性能研究

用一种新的低温过程制备了SrBi2Ta2O9铁电薄膜。在Sol-Gel方法中用Pt/Ti/SiO2/Si作衬底,研究了薄膜的结构和电特性。SrBi2Ta2O9薄膜在淀积Pt上电极之前和之后都要退火,第一次退火在760乇氧压下600℃时退火30分钟,在第二次退火后薄膜结晶良好。