HgCdTe晶体上Cd和Te的阴极共沉积

在ＨｇＣｄＴｅ晶体表面上用电化学方法得到了Ｃｄ和Ｔｅ的共沉积．所用的电解质由Ｈ２ＳＯ４；ＣｄＳＯ４和ＴｅＯ２的水溶液所组成．稳态沉积电流密度随着沉积电位更负，电解质温度升高和ＴｅＯ２浓度的增加而增大．Ｘ光衍射分析证实，当沉积电位比－０．７０Ｖ（ｖｓＳＣＥ）更负时，沉积膜由ＣｄＴｅ和Ｃｄ所组成．当沉积电位比－０．６７５Ｖ更正时，沉积膜为化学计量的多晶ＣｄＴｅ，其（１１１）面为优先生长的晶面族．沉积膜的显微照相可能表明多层ＣｄＴｅ的扁平晶粒逐步长大连成一体后而完全复盖底晶．俄歇电子谱的深度剖面分析显示在所沉积的条件下，底晶中的Ｈｇ向ＣｄＴｅ沉积膜内有较深的扩散．     

常压MOCVD制备MgO薄膜的研究

本文首次报道用常压金属有机化学气相沉积（ＡＰ－ＭＯＣＶＤ）在Ｓｉ（１００），ＳｉＯ２／Ｓｉ（１００）和Ｐｔ／Ｓｉ（１００）衬底上外延高质量的ＭｇＯ薄膜。研究了衬底温度与薄膜的取向性关系和ＭｇＯ薄膜的潮解特性。高纯ｍａｇｎｅｓｉｕｍａｃｅｔｙｌａｃｅｔｏｎａｔｅ［ｂｉｓ（２，４－ｐｅｎｔａｎｅｔａｎｅ－ｄｉｏｎｏ）ｍａｇｎｅｓｉｕｍ］［Ｍｇ（ＣＨ２ＣＯＣＨ２ＣＯＣＨ３）２］作为金属有机源，扫描电镜（ＳＥＭ），透射电镜（ＴＥＭ）和Ｘ－ＲＡＹ衍射实验显示，在较低的衬底温度（～４８０℃）下一次淀积成单晶膜。薄膜均匀，致密，结晶性和取向性很好，衬底温度（Ｔｓ）在４００℃到６８０℃之间，在Ｓｉ（１００）衬底上生长的ＭｇＯ薄膜都具有［１００］取向，在Ｓｉ（１００）、ＳｉＯ２／Ｓｉ（１００）和Ｐｔ／Ｓｉ（１００）衬底上生长的ＭｇＯ薄膜也都具有［１００］取向。     

AMT保护青铜的研究

采用电化学方法和ＸＰＳ、ＡＥＳ法研究５－氨基－２－巯基－１、３、４－噻二唑（ＡＭＴ）在青铜表面形成的保护膜。结果表明，ＡＭＴ溶液处理后的青铜试片在ｐＨ值为７的０．５ｍｏｌ／ＬＮａ２ＳＯ４和５％ＮａＣｌ溶液中，其腐蚀过程受到了明显抑制，是由于ＡＭＴ在青铜表面形成Ｃｕ（Ｉ）ＡＭＴ络合物膜，其结构为Ｃｕ｜Ｃｕ２Ｏ｜Ｃｕ（Ｉ）ＡＭＴ。     

DMF中电沉积制备Yb-Co合金膜

研究了于室温下含有少量水的ＹｂＣｌ３－ＣｏＣｌ２－ＤＭＦ溶液中电沉积制备Ｙｂ－Ｃｏ合金膜。ＥＤＡＸ和ＸＲＤ分析表面：在０．１０ｍｏｌ／Ｌ ＹｂＣｌ３－０．１０ｍｏｌ／Ｌ ＣｏＣｌ２的ＤＭＦ电镀液中,以控制电位为－２．７５Ｖ（ＳＣＥ）进行恒电位电解,以控制电流密度为１００Ａ／ｍ＾２进行恒电流电解或以控制脉冲电流密度为１５０Ａ／ｍ＾２进行脉冲电解,可以得到不同形态和Ｙｂ含量的共沉积合金膜,且膜层光滑、     

新型双相铸造不锈钢的组织与耐蚀性能

设计了用于“Ｈ＿２ＳＯ＿４为１１０．５ｇ／Ｌ，Ｎａ＿２ＳＯ＿４为３８７ｇ／Ｌ，ＺｎＳＯ＿４为１４．４ｇ／Ｌ，密度为１．３５ｇ／ｃｍ￣３，温度为５０℃”工况介质的新型铸造不锈钢的金相组织与化学成分。采用金相显微镜和Ｘ－射线衍射的方法分析了钢的金相组织，并对该钢的耐腐蚀性做了研究，同时与性能优良的９０４和ＣＤ４ＭＣｕ钢进行了对比。试验结果表明ＫＳ－２试验钢经１１００℃固溶处理后的耐腐蚀性能明显优于对比合金９０４和ＣＤ４ＭＣｕ钢，具有广阔的应用前景。     

大型煤气过江管道外加电流阴极保护

阐述了在我国首次将外加电流阴极保护技术应用于大口径过江钢质管道的防腐工程，一次调试成功。通过长期运行，充分证明了阴极保护系统工作正常、性能稳定可靠。从电位监测数据明显看出，不仅达到了设计指标，钢管电位均在－０．９６～－１．０６Ｖ范围内（相对Ｃｕ／ＣｕＳＯ＿４参比电极），而且整条管线电位分布均匀，处于最佳保护状态。     

气相色谱法研究碳在氧阴极过程中的腐蚀

用气相色谱法研究和为氧阴极的碳材料在Ｎａ２Ｂ４Ｏ７和Ｎａ２Ｂ４Ｏ７－Ｎａ２ＣＯ３介质中腐蚀,结果表明,在较负电位下（－０．４－０．５Ｖ,０．１ｍｏｌ／Ｌ ＮａＯＨ）,检出ＣＯ和Ｃ瑟空白相同,说明碳腐蚀主要由电化学作用所致。     

过硫酸钾—脲氧化还原引发的甲基丙烯酸乙酯基三甲基氯化铵反…

研究了以ｓｐａｎ－８０为乳化剂和过硫酸钾－脲引发体系下，甲基丙烯酸乙酯基三甲基氯化铵反相乳液聚合的动力学，得出在「Ｋ２Ｓ２Ｏ８」为１２．３－７３．８μｍｏｌ．Ｌ＾－１．「ＣＯ（ＮＨ２）２」ｏ为０－０．９５ｍｍｏｌＬ＾－１，乳化剂为４１．７５－６６．８０ｇ．Ｌ＾－１范围内的聚合速率表达式：Ｒｐ＾∞「ＤＭ．ＭＣ」＾１．７１「Ｋ２Ｓ２Ｏ８」＾０．２８「ＣＯ（ＮＨ２）２」＾０．０１「３」＾－１．１８，ＢＣ     

SOCl_2/TiCl_4引发体系的α-蒎烯/苯乙烯阳离子共聚反应研究 Ⅰ.SOCl_2/TiCl_4的共聚合性能研究

通过对ＳＯＣｌ２／ＴｉＣｌ４引发体系的α－蒎烯（Ｍ１）／苯乙烯（Ｍ２）共聚产物进行ＧＰＣ、１ＨＮＭＲ以及微臭氧化－薄层层析法等分析表征，证明该引发体系能在宽广的单体投料比范围内实现有效共聚。在确认仅生成共聚物的反应条件下，采用Ｍａｙｏ－Ｌｅｗｉｓ式积分法测得该体系在－３０℃、［ＳＯＣｌ２］＝２０ｍｍｏｌ／Ｌ、［ＴｉＣｌ４］＝６０ｍｍｏｌ／Ｌ、ＣＨ２Ｃｌ２溶剂中的竞聚率分别为苯乙烯ｒ２＝２．３１±０．１５；α－蒎烯ｒ１＝０．５２±０．０６。     

NaH2PO2在Pt电极上电化学还原的研究

用循环伏安法研究了ＮａＨ２ＰＯ２在Ｐｔ电极上的电化学行为,结果表明：ＮａＨ２ＰＯ２在０．５ｍｏｌ／Ｌ ＮａＣｌ溶液中在－０．７５Ｖ左右有一个还原峰,其峰值随着ＮａＨ２ＰＯ２的浓度的增加,随溶液的ｐＨ值的降低而增加。     

An investigation on the electrochemical behavior of the Co/Cu multilayer system

Co/Cu multilayers were deposited in a sulfate solution by controlling the current and potential for the deposition of cobalt and copper layer respectively. The electrochemical behavior of these multilayers was studied by cyclic voltammetry and current transients. In addition, a mathematical analysis was used to characterize the electrodeposition system. Simultaneously, the nucleation and growth mechanisms were monitored by these techniques. In this case, the results clearly showed that electrodeposition of cobalt layers was a kinetically controlled process while the reduction of copper ions was a diffusion-control process. Although nucleation mechanism of the single Co deposit was found as a progressive system, it was found as an instantaneous system with three-dimensional growth mechanism in the Co/Cu bilayer deposition. Atomic Forced Microscopy images of the Co/Cu multilayer also confirmed the aforementioned nucleation mechanism, where it was expected that the growth of multilayer films would form a laminar-type structure containing a large number of equally-sized rounded grains in each layer.     

电沉积法制备块体纳米晶材料的研究进展

综述了电沉积法制备块体纳米晶材料的原理;阐述了电流密度、电流波形、有机添加剂等工艺参数对沉积层晶粒尺寸的影响;介绍了直流电沉积、脉冲电沉积、喷射电沉积和复合电沉积等几种常见的电沉积方法;概述了电沉积法制备块体纳米晶材料的国内外研究现状;探讨了电沉积块体纳米晶材料的力学性能、磁学性能、耐蚀性能、热稳定性及其应用前景.     

Cu-In合金硒化法制备CuInSe_2薄膜

采用三电极体系恒电压电沉积法制备了Cu-In薄膜,经硒化退火生成CuInSe_2薄膜.采用循环伏安法研究了电沉积Cu-In的循环伏安特性,确定其最佳沉积电位在-0.75V左右,Cu与In的化学计量比为1.1,达到了理想前驱体的Cu与In的化学计量比.研究了不同沉积电位下材料组成、结构与性能的影响.硒化后,Cu与In的化学计量比为1,1时形成了比较单一的CuInSe_2黄铜矿相结构.     

Reusable platinum nanoparticle modified boron doped diamond microelectrodes for oxidative determination of arsenite

Boron doped diamond (BDD) macro- and microelectrodes were modified by electrodeposition of platinum nanoparticles using a multipotential step electrodeposition technique and used for the oxidative determination of arsenite, As(III). The formation of Pt nanoparticles was evident from cyclic voltammetry measurement, whereas AFM and SEM revealed the size and size distribution of deposited Pt nanoparticles. Raman spectroscopy illustrated a correlation between the typical BDD signature and the number of platinum deposition cycles. Linear sweep voltammetry performed with the modified BDD microelectrode outperformed its macrocounterpart and resulted in very low detecting currents with enhanced signal-to-noise ratios. With linearity up to 100 ppb and a detection limit of 0.5 ppb, the electrochemical system was applicable for processing tap and river water samples. Over 150 repetitive runs could be performed, and electrochemical etching of platinum allowed the reuse of the BDD microelectrode. The presence of copper and chloride ions, the two most severe interferents at levels commonly found in groundwater, did not interfere with the assay.     

Nucleation and growth of copper particles on Pt and Pt/poly-3-methylthiophene modified electrode in presence of Cl complexing agent

The kinetics of electrochemical deposition of copper particles from Cu²⁺ solution on platinum and poly-3-methylthiophene modified platinum electrode was studied in potentiostatic conditions in presence of Cl⁻ anions. The complex behavior of current transients suggests that the deposition process involves several stages with different kinetics. Results obtained on platinum show that after an initial adsorption process, the copper deposition is accomplished through two different models: a three-dimensional nucleation and growth under diffusive control (3DPD model) and a progressive nucleation and two-dimensional growth (2DP model). The analysis of current transients recorded on platinum poly-3-methylthiophene modified electrode (Pt/PMT) shows a very different behavior. On Pt modified electrode a process of growth related to a semi-infinite diffusion to a planar surface was accompanied by two different mechanisms of nucleation and growth: a three-dimensional nucleation and growth with no diffusive control (3DP model) and an instantaneous nucleation with two-dimensional growth (2DP model).     

Growth characteristics of copper of tungsten grown through cementation,vapor deposition and electroplating

The growth characteristics of thin copper deposits grown through cementation, electrodeposition and vapor deposition were evaluated through imaging the coated samples in the field ion microscope at 78 K utilizing a 90% He-10% Ne gas mixture. Although the thicknesses of overgrowths were found to be varied with the method and time of deposition, copper in thin overgrowths (less than approximately 50 atom layers) was observed to grow epitaxially on the tungsten substrate surface. In thicker layer growths the epitaxial growth was found to change to a misfit zone with excessive defect structures followed by a polycrystalline copper arrangement. A prominent feature of these thick overgrowths was observed to be their instability under field-induced stresses of the field ion microscope imaging, thus rendering a layer-by-layer evaluation through the three-zone arrangement quite difficult.The initial tungsten surface was recovered upon controlled field evaporation only in the vapor deposition experiments while in the electroplating and cementation experiments the tungsten surface recovered was quite different from the original substrate imaged, thus indicating that an initial dissolution followed by deposition of copper had taken place in the electroplating and cementation processes. In spite of this initial surface reaction, the copper overgrowths were found to be deposited epitaxially. The observed epitaxy of the face-centered cubic copper on body-centered cubic tungsten substrate end forms at thin coverages was consistent with earlier studies of vapor deposition utilizing the copper overgrowth- tungsten substrate system.     

Factors controlling the electrodeposition of metal nanoparticles on pristine single walled carbon nanotubes

The electrodeposition of metal (Pd and Pt) nanoparticles on networks of pristine single walled carbon nanotubes (SWNTs) has been investigated using a microelectrochemical cell. A microcapillary containing electrolyte solution and a reference electrode is contacted with a silicon oxide substrate bearing a SWNT network, connected as the working electrode. Electrodeposition is promoted by applying a potential between the SWNT network and the reference electrode. By combination of analysis of the resulting current-time curves with atomic force microscopy and field emission scanning electron microscopy imaging of the network surfaces after electrodeposition, the nature of metal nanoparticle formation on SWNTs has been elucidated. In particular, the parameters controlling nanoparticle number density, distribution, and size have been identified, with short deposition times and high driving forces favoring the formation of ultrasmall particles at high density. Capacitance and network resistance effects are minimized in the microcapillary configuration, making it possible to accurately analyze short time-scale deposition processes (millisecond time scale). Furthermore, it is also possible to make many measurements on a pristine sample, simply by moving the position of the microcapillary to a new location on the substrate.     

Dynamic microscopy of nanoscale cluster growth at the solid-liquid interface

Dynamic processes at the solid-liquid interface are of key importance across broad areas of science and technology. Electrochemical deposition of copper, for example, is used for metallization in integrated circuits, and a detailed understanding of nucleation, growth and coalescence is essential in optimizing the final microstructure. Our understanding of processes at the solid-vapour interface has advanced tremendously over the past decade due to the routine availability of real-time, high-resolution imaging techniques yielding data that can be compared quantitatively with theory. However, the difficulty of studying the solid-liquid interface leaves our understanding of processes there less complete. Here we analyse dynamic observations--recorded in situ using a novel transmission electron microscopy technique--of the nucleation and growth of nanoscale copper clusters during electrodeposition. We follow in real time the evolution of individual clusters, and compare their development with simulations incorporating the basic physics of electrodeposition during the early stages of growth. The experimental technique developed here is applicable to a broad range of dynamic phenomena at the solid-liquid interface.     

喷射电铸工艺参数对铜铸层形貌的影响

介绍了喷射电铸的相关原理,运用扫描电镜分析了相关工艺参数(电流密度、电解液喷射速度、扫描速度、扫描层数)对铜沉积层微观结构的影响,采用工艺参数:电流密度300A/dm2,电解液喷射速度4m/s,喷嘴扫描速度10mm/s制备了纳米铜块体。结果表明喷射电铸可大大提高电铸的电流密度,远高于传统电铸电流密度;电流密度、喷射速度、扫描速度以及扫描层数都对沉积层的表面生长形态有较大的影响,使用低电流密度、高喷射速度和快的扫描速度和少的扫描层数有利于获得平整、致密的沉积层。     

Fabrication of poly- and single-crystalline platinum nanostructures using hole-mask colloidal lithography, electrodeposition and annealing

Colloidal lithography (CL) is a generic name for a collection of nanolithographic techniques, based on using colloidal nanoparticles as pattern (mask)-defining entities to produce various nanostructures. A key step in CL processes is the deposition, usually by evaporation or sputtering, of the material that makes up the final nanostructures. We have for the first time combined a special version of CL, called hole-mask colloidal lithography (HCL), with electrodeposition. We demonstrate how electrodeposition of Pt onto Au and carbon substrates, through a lithographic mask, can be used to prepare well-defined nanostructured surfaces. The results are compared with evaporated structures and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and cyclic voltammetry. Specific results are: (i) electrodeposition generates structures with very good adhesion, (ii) due to differences in the deposition mechanism, structures with much larger aspect (height/width) ratio can be made with electrodeposition than with evaporation and (iii) the originally deposited polycrystalline nanoparticles can be annealed into single crystals, as demonstrated by electron diffraction, SEM and TEM, before and after annealing, which is of great value for fundamental (electro)catalysis studies.