多孔金属材料连续电沉积过程最优化设计

为了对电沉积法制备多孔金属的设备制造和在线控制提供理论指导,针对多孔金属的电阻特性,初次建立了垂直方式运动状态下,带状多孔金属材料连续多级恒电流密度电沉积模型,推导出阳极长度、形状、安装位置、运行速度和总电流的计算公式,对电沉积法制备多孔金属材料的生产线设计和在线控制具有应用价值．     

Nanostructured ZnO Films Electrodeposited on Hydrophilic Substrate Utilizing Cooperative Surface Assembly

Nanoporous amorphous ZnO films with lamellar structure were electrodetposited on the hydrophilir substrate by utilizing cooperative surface aussembly of anionic sodium dodecyl sulfonate （ SDS ） at a very low concentration and inorganic species Zn （ NO3 ）2 under the influence of an electrostatic potential. The deposited films were characterized by X-ray diffraction （XRD） in the range of lou, angle and wide-angle, X-ray photoelectron spectroscopy （ XPS）, scanning electron microscopy （SEM）, and UV-Vis light absorption spectroscopy.The formation mechanism of the films was elementarily discussed.     

Effects of Substrate Local Strain on Microstructure of Electrodeposited Aluminum Film

1 IntroductionElectrodeposition,has been widely usedin electron-ics, automobile and airliner industry, and has been anobject of intense research over the past years . Comparedwith other methods for preparing coatings ,the electro-deposition has several advantages , such as least cost ,controllability, avoidance of thermal stress and higherproduction, which can produce functional coatings withresistance to corrosion and wear and low coefficient offriction in engineering field[1 ,2]. Moreover ,t…     

溶胶-凝胶模板法制备有序多孔二氧化铈薄膜

采用乳液共聚法制备了聚苯乙烯-丙烯酸羟乙酯[P(St-HEA)]微球,通过流延成膜法制备了P(St-HEA)薄膜,再利用溶胶-凝胶模板法煅烧得到有序多孔二氧化铈(CeO2)薄膜.采用红外光谱、扫描电镜以及X射线衍射分析对P(St-HEA)微球单分散性及有序多孔CeO2薄膜表面形貌和结构进行了表征.结果表明,当丙烯酸羟乙酯(HEA)用量占总单体的用量低于10%(质量分数)时,制备的P(St-HEA)微球单分散性和表面较好.通过P(St-HEA)的胶体晶体模板制备了有序多孔CeO2薄膜,所得孔径约为190 nm,X-射线衍射分析显示有序多孔CeO2薄膜是立方萤石结构.     

高孔密度阳极氧化铝模板的制备及结构表征

采用两步氧化法制备出双面多孔阳极氧化铝模板（AAO）,并进一步发展了模板通孔工艺,得到单层高密度多孔氧化铝模板,并用XRD、SEM和AFM对模板结构进行了表征．结果表明,草酸环境下制备的AAO模板孔排列高度规整,孔密度为10^11个／cm^2量级,孔径为45～55nm,孔间距为100～120nm．     

沉积金属微粒的多孔氧化铝薄膜偏光性能探讨

从理论和试验两方面探讨了沉积金属微粒的多孔氧化铝薄膜的偏光特性，结果表明：铝多孔膜的特殊结构，使在其中沉积的金属微粒能定向排列，表现出光的各向异性，在近红外波段约2700nm处，表现出良好的偏光特性，通过对膜层中沉积金属微粒种类以及入射光角度调整，可对其偏光特性进行调节。     

沉积温度对ZnO薄膜结构形貌及光学性能的影响

以Zn(NO3)2·6H2O为前驱体,采用超声喷雾热解法在玻璃衬底上沉积了ZnO薄膜,采用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外光谱仪(UVS)等对所得ZnO薄膜进行表征,研究了沉积温度对ZnO薄膜的结构、微观形貌及光学性能的影响。结果表明,沉积温度为500℃时所制备的薄膜质量最佳,形成的是六角纤锌矿ZnO结构,且薄膜沿(002)晶面择优取向生长显著,薄膜表面光滑致密,晶粒细小均匀,尺寸在50~60nm。薄膜表现出良好的光学性能,可见光透过率可达87%。     

铁纳米线阵列的制备及磁性研究

采用二次阳极氧化法制备高度有序的多孔氧化铝模板,以高度有序的阳极氧化铝为模板,用交流电沉积的方法以较低的电压在孔洞中组装了铁纳米线有序阵列.采用场发射扫描电镜(FESEM)对模板和纳米线的形貌和结构进行了表征,采用物理特性测量系统(PMMA)测量了铁纳米线的磁滞回线,结果表明纳米线是均匀连续的,直径为50 nm左右,纳米线在平行于纳米线轴的方向的矫顽力为2 259 Oe,矩形比为0.92,铁纳米线阵列有高的磁各向异性,适用于垂直磁记录介质.     

生长温度对掺钛氧化锌薄膜光学性质的影响

以氧化锌钛陶瓷靶作为溅射源,采用磁控溅射技术在玻璃衬底上制备了掺钛氧化锌(TZO)透明导电薄膜,通过X射线衍射仪和分光光度计测试表征以及全光谱拟合法分析,研究了生长温度对TZO薄膜晶体结构和光学性质的影响.结果表明:所有TZO样品均为六角纤锌矿结构,并具有(002)择优取向,生长温度对薄膜晶粒尺寸和光学透射率的影响较明显,而对折射率、消光系数和光学能隙的影响较小.当生长温度为200℃时,TZO薄膜的晶粒尺寸最大,可见光范围平均透射率(含衬底)为76.1%,对应的直接光学能隙为3.45 eV.     

非晶态ZnO薄膜的微结构及光学性质

采用溶胶-凝胶法在玻璃衬底上制备了非晶态ZnO薄膜。用X射线衍射仪(XRD)、扫描探针显微镜(SPM)研究了非晶态ZnO薄膜的晶相和微观形貌,用紫外-可见光光度计和荧光光度计研究了非晶态ZnO薄膜的光学特性。测试结果表明,XRD谱没有任何衍射峰,表明所制备的ZnO薄膜确实是非晶态;非晶态ZnO薄膜的表面平整、光滑,表面粗糙度均值为1.5 nm;在可见光区有很高的透过率,最高值为90%;光学带隙为3.39 eV;其PL谱显示在紫外区384 nm处有较强的紫外发射。     

Morphology and growth of porous anodic oxide films on Ti-10V-2Fe-3Al in neutral tartrate solution

Porous anodic oxide films were fabricated galvanostatically on titanium alloy Ti-10V-2Fe-3Al in ammonium tartrate solution with different anodizing time. Scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM) were used to investigate the morphology evolution of the anodic oxide film. It is shown that above the breakdown voltage, oxygen is generated with the occurrence of drums morphology. These drums grow and extrude, which yields the compression stress. Subsequently, microcracks are generated. With continuous anodizing, porous oxides form at the microcracks. Those oxides grow and connect to each other, finally replace the microcrack morphology. The depth profile of the anodic oxide film formed at 1 800 s was examined by Auger electron spectroscopy (AES). It is found that the film is divided into three layers according to the molar fractions of elements. The outer layer is incorporated by carbon, which may come from electrolyte solution. The thickness of the outer layer is approximately 0.2–0.3 μm. The molar fractions of elements in the intermediate layer are extraordinarily stable, while those in the inner layer vary significantly with sputtering depth. The thicknesses of the intermediate layer and the inner layer are 2 μm and 1.0–1.5 μm, respectively. Moreover, the growth mechanism of porous anodic oxide films in neutral tartrate solution was proposed.     

AlN能带及态密度的密度泛函理论研究

文章采用基于密度泛函理论的平面波超软赝势法计算了A lN晶体的能带结构和态密度曲线。研究表明,A lN的价带由-15.3eV－-12.3eV的下价带和-6.2eV－0eV的上价带区组成,价带顶出现三个子带：简并的重空穴、轻空穴和自旋-轨道耦合所分裂出来的劈裂带（距带顶0.2eV）;导带主要是由A l的3s、3p态电子和N的2p态电子构成的;理论预测A lN价带空穴具有大的有效质量;A lN是一种直接宽禁带半导体,带隙为4.7eV,比较起来该结果优于一些文献中的计算值。     

溶胶-凝胶法制备氧化锌薄膜

采用了溶胶-凝胶工艺在普通的玻璃载玻片上成功地制备出具有c轴择优取向性、高的可见光透光率、平整均匀的氧化锌薄膜。通过XRD、AFM以及UV光谱仪等分析,其结果表明:所制备的氧化锌薄膜具有纤锌矿型结构,表面均匀致密,薄膜晶粒尺寸大约在40~90 nm,溶胶浓度增大时,其晶粒大小呈增大的趋势。随着涂膜层数的增加,薄膜的(002)方向的取向度增加。薄膜在可见光区的光透过率>85%,在近紫外光波段透射率急剧减小,对应的禁带宽度为3.34 eV。     

磁控溅射制备Ti-Zn-O复合薄膜及其光学性质研究

TiO2是作为一种宽禁带半导体材料可作为紫外器件,但因其间接带隙结构、禁带宽度仅为3.0eV等特点,严重影响其应用范围。本文利用共溅射技术,通过Zn掺杂,在K9玻璃基底上制备了Ti-Zn-O复合薄膜,并研究了Zn溅射功率对其结构及光学性质的影响。结果显示：所制备的薄膜为ZnTiO3和不饱和TiO2的复合结构,随着Zn粒子的溅射能量增加,晶粒尺寸和表面粗糙度增加,并可将薄膜本征吸收边蓝移至3.61eV。     

Study on pulsed laser ablation and deposition of ZnO thin films by L-MBE

ZnO,as a wide-band gap semiconductor,has recently become a new research fo-cus in the field of ultraviolet optoelectronic semiconductors. Laser molecular beam epitaxy(L-MBE) is quite useful for the unit cell layer-by-layer epitaxial growth of zinc oxide thin films from the sintered ceramic target. The ZnO ceramic target with high purity was ablated by KrF laser pulses in an ultra high vacuum to deposit ZnO thin film during the process of L-MBE. It is found that the deposition rate of ZnO thin film by L-MBE is much lower than that by conventional pulsed laser deposition(PLD) . Based on the experimental phenomena in the ZnO thin film growth process and the thermal-controlling mechanism of the nanosecond(ns) pulsed laser abla-tion of ZnO ceramic target,the suggested effective ablating time during the pulse duration can explain the very low deposition rate of the ZnO film by L-MBE. The unique dynamic mechanism for growing ZnO thin film is analyzed. Both the high energy of the deposition species and the low growth rate of the film are really beneficial for the L-MBE growth of the ZnO thin film with high crystallinity at low temperature.     

纳米氧化锌的制备及表面改性

以草酸与醋酸锌为原料,用室温固相合成法首先合成出前驱物二水合草酸锌,再经过460℃热分解2 h,得到纳米氧化锌.分别用十二烷基苯磺酸钠,硬脂酸钠对产物进行改性,通过X-射线粉末衍射、透射电镜对产物进行物相分析及形貌表征,用分光光度计研究了其在有机介质中的分散性.结果显示改性的纳米氧化锌粒径在30~70 nm,其分散性能明显好于未改性的纳米氧化锌.     

Self-assembled synthesis of porous TiO2 film on the electrophoretic-deposited titanate nanoribbon film

The porous TiO₂ film was self-assembled on the surface of electrophoretic-deposited titanate nanoribbon film without the addition of templates by using TiF₄ as the precursor.It was found that the hydrolysis of TiF₄ was accompanied with the self-assembly processes of TiO₂ nanoparticles on the surface of electrophoretic-deposited titanate nanoribbon film,resulting in the formation of porous TiO₂ structures.Titanate nanoribbon film was demonstrated to provide the active sites for the effective self-assembly of porous TiO₂ nanostructures owing to a large amount of hydroxyl groups.Compared with the nonporous TiO₂ film,the prepared porous TiO₂ films obviously showed an enhanced photocatalytic activity,which could be attributed to the rapider diffusion and more efficient transport of various reactants and products during photocatalytic reaction in the porous structures.     

烧结温度对BaTiO3多孔陶瓷性能的影响

采用水基冷冻浇注法制备了具有层状结构的BaTiO3多孔陶瓷,研究了烧结温度对多孔陶瓷微观形貌、收缩率、孔隙率及介电性能的影响,并探讨了高岭土悬浮剂在烧结过程中所起的作用.研究结果表明:高岭土含量4wt%的样品收缩率从1 200℃时的27%升高到1 220℃时的56%,同时孔隙率从78%下降到56%,高岭土含量8wt%的样品收缩率从1 200℃时的30%升高到1 220℃时的61%,同时孔隙率从72%下降到39%;高岭土在烧结过程中起到烧结助剂的作用;烧结温度升高会使孔径变小并导致孔隙排列由有序结构向无序结构转变.高岭土含量为8wt%,烧结温度1 200℃时,可以得到分布均匀的层状结构多孔陶瓷;高岭土含量为4wt%,烧结温度1 220℃时可得到介电常数130的多孔陶瓷.     

Effect of silver growth temperature on the contacts between Ag and ZnO thin films

Highly c-axis oriented ZnO thin films were deposited on Si substrates by the pulsed laser deposition (PLD) method. At different growth temperatures, 200 nm silver films as the contact metal were deposited on the ZnO thin films. The growth temperatures have great influence on the crystal quality of Ag films. Current-voltage characteristics were measured at room temperature. The Schottky contacts between Ag and ZnO thin films were successfully obtained when silver electrodes were deposited at 150°C and 200°C. Ohmic contacts were formed while the growth temperatures were lower than 150°C or higher than 200°C. After analysis, the forming of Ag/ZnO Schottky contacts was shown to be dependent on the appearance of the p-type inversion layer at the interface between Ag and ZnO layers.     

退火温度对锆酸铅薄膜光学性能的影响

用溶胶-凝胶法在石英玻璃基片上成功地制备了PbZrO3(PZ)薄膜．X射线衍射分析结果表明晶化好的PZ薄膜,是多晶钙钛矿结构．750℃晶化的薄膜,晶粒尺寸为30～50nm．用紫外-可见光分光光度计在波长200～900nm范围内,测量了不同温度退火的PZ薄膜的透射率,结果表明450、600、750℃退火的薄膜样品,其光学吸收边分别为4．11、4．56、4．59eV．