p—Si上激光诱导局部沉积铂

现代电子工业中，电子器件基体材料多为半导体或绝缘体，因此，不用外加电源的激光诱导微区沉积技术引起了人们的重视［‘－‘j．这种高度选择性、高速沉积性、工艺简单的技术在电接插件局部镀，多芯层模块制作中的基板联线，加成法制造微带电路及其修复，半导体集成电路中布线的修复等方面有着广泛的应用前景．激光诱导液相金属沉积可在多种基体上，多种电解质溶液中进行”－“’，本课题组自90年代初从事激光镀的研究以来，已利用Ar”激光在硅片上分别实现了Ni－P合金「“］和Cll［“j的镀覆．本文采用3种不同的镀铂溶液作为电解质，在…     

从氨性柠檬酸溶液中电沉积Ni-Mo的机理研究

含钼大于约27％（质量分数）Ni－Mo合金，具有较高的耐蚀性，特别是在盐酸和硫酸溶液中，其耐蚀性优于SUS304不锈钢［1］．因此，人们对该种合金的电沉积进行了广泛的研究［1－4］．对合金共沉积机理也作了一定的研究．一般认为，钼不能单独进行电沉积，但它可以同铁族元素共沉积［5］．对钼与铁族元素的共沉积机理，人们已提出了几种假设．一般认为［3］，钼可能是多步还原，即六价钼首先被电化学还原成低价钼化合物，而后由吸附在诱导金属（铁族元素）上的原子氢进一步还原成合金中的零价钼，为了进一步弄清Ni－Mo合金的共沉积机理，本…     

氧化锌-银复合纳米粒子的制备：吸收光谱和荧光光谱

金属和半导体纳米粒子的制备及性质的研究是当今材料科学和物理化学的热门课题［1－6］．在利用太阳能光降解环境污染物、生物传感器以及光生物等方面这些纳米粒子都具有实际应用的可能性．对纳米粒子表面进行修饰而形成的复合纳米粒子可以有效地调整单一颗粒的表面性质甚至颗粒的稳定性．另外，复合纳米粒子的制备对研究纳米粒子的尺寸量子化效应、非线性光学性质及其它光电性质都有重要的意义．人们已成功地制备了许多复合金属－金属纳米粒子，如Cu－Ag［7］，Ag-Pd［8］及Ag－Pt［9］等．关于复合半导体－半导作纳米粒子也有报导，如C…     

α-氨基肟配合物[M(Ⅱ)(PnAO)-H]的循环伏安研究

利用循环伏安法研究了脂族配合物［M（Ⅱ）（PnAO）H］＋（M＝Co，Ni，Cu，Pd）的氧化还原行为，得到了相应的电化学参数，提出了电化学－化学偶联过程的反应机理．讨论了不同金属离子及溶液的pH值对类芳香金属配合物生成的影响，阐明了这类化合物形成的动力学因素。     

ρ-Si上电沉积制备镍-磷非晶薄膜催化剂

非品态合金作为一类新型催化材料，越来越引起人们的广泛关注．Ni－P非晶态合金催化剂的催化加氢性能研究尤为活跃［‘，’］，研究结果表明其活性明显高于Ni－P晶态合金和比表面积相当的Ni粉L＼从而具有实用价值．传统的非品态合金催化剂的制备方法，如真空蒸镀、真空溅射、液相急冷及离子注入等，存在设备复杂、耗能大，难以批量生产等缺点；化学法可制备粒度均匀的催化剂＊；但给提纯带来了一定困难，而电沉积制备非晶薄膜催化剂由于具有纯度高、能耗低、制作方便等优势而倍受青睐问利用半导体做载体沉积Ni－P非晶态合金，在光电催化…     

Mo－Ni合金电沉积及其电催化性能研究

Ｍｏ－Ｎｉ合金电沉积及其电催化性能研究林文修，言枝（福建师范大学化学系福州３５０００７）析Ｈ＿２的电催化电极反应在电化学能量转换、电合成、金属沉积和腐蚀中具有重要意义，而探索和选择优良的过渡金属电催化剂是研究析Ｈ＿２电催化阴极的主要方向￣［１］。１９...     

氧化铁超微粒的光电化学特性

近十年来,。J、粒1（smalParticle）或超微粒f（ultrafinParticle）研究在化学、物理、材料学科等领域中兴起［‘一‘］．超微粒子是指粒径在Inm～几十n－m范围的物质山．快体（如金属、半导体）的性质并不是单个原子或分子本身的性质,而是由许多原子或分子在晶体中的周期排列造成的．当晶体的尺寸在纳米级范围内连续减小时,存在一个从金属或半导体的性质到分子或原子的性质的逐渐过渡．在这个变化范围内,半导体的光学性质有很大变化,金属的电化学行为也发生了变化．这被称为“尺寸量子化效应’．同时当半导体的尺寸在纳米范围时,其…     

电沉积银铟硒薄膜的(光)电化学特性研究

银铟硒是继铜铟硒之后新发展起来的另一种能源、信息功能材料，它的禁带宽度Ｅｇ＝１．２０ｅＶ，更接近于光电转换效率最高的太阳能电池所应具有的能隙值［１］，因此具有广泛的应用前景．早在六十年代，前苏联就对银铟硒的物理性质及电子特性有过报道．目前有关光电化学电池（ＰＥＣ）所利用的银铟硒薄膜材料的制备大多是采用大晶粒熔融生长法［２，３］．８０年代，ＲａｖｉｅｎｄｒａＰ．Ｔ．Ｋ．Ｓｈａｒａｍａ［４］曾报道应用电沉积法制作ｐ＿ＡｇＩｎＳｅ２／ＣｄＳ液结太阳能电池，但真正利用电化学沉积制备银铟硒的报道不多，由电…     

铜和金纳米线阵列上SCN-的表面增强拉曼光谱

纳米材料的制备和性质研究已成为化学和物理等领域中的热点［１～４］．例如,一些纳米尺度的金属表现出极高的催化活性;一些低维的半导体纳米点（零维）、线（一维）、面（二维）材料被认为在半导体信息工业中将占有举足轻重的地位．最近有关金属和半导体纳米线的研究正在兴起,其特殊的电学和光学性质引起了广泛兴趣,并有可能制备成为各类尺寸极小的纳米电极［２］．迄今已有多种技术用于研究和表征金属以及半导体纳米线的特殊性质［２,５～９］,其中紫外可见吸收光谱和荧光光谱是广泛使用的表征纳米线光学性质的技术［２,５,６］．…     

半导体硅上激光诱导化学沉积镍薄膜

由于激光具有高能量密度、高单色性以及良好的相干性,在表面处理技术中的应用越来越广泛．在金属、半导体和高聚物基体上,从水溶液进行激光诱导的化学沉积引起了人们的极大注意,这种工艺在微电子电路及器件上有广泛的应用前景．与传统的化学镀相比,它具有明显的优越性...     

铅在铜上电沉积的原位椭圆偏振法

采用循环伏安法(CV)和原位椭圆偏振法(SE)研究铅在铜电极上的电沉积行为。 原位椭圆偏振参数Ψ和Δ值的变化率在CV图峰电位处同时出现极值。 通过建立单层膜模型描述“电极-溶液”界面的结构并对椭圆偏振光谱数据进行拟合得到铅沉积层厚度随电位的变化规律。 拟合结果显示,铅在铜电极上的电沉积有3个不同的沉积速率,-0.20～-0.35 V之间沉积速率为0.003 nm/mV,-0.35～-0.48 V之间沉积速率为0.025 nm/mV,-0.48～-0.60 V之间沉积速率为0.116 nm/mV,由此表明铅的电沉积分为3个不同阶段：欠电位沉积阶段、欠电位沉积向本体沉积的过渡阶段和本体沉积阶段。     

Different methods of preparing electrode from single-wall carbon nanotubes and their effect on the Li ion insertion process

Single-wall carbon nanotube (SWNT) is processed in three different ways: (1) coating a film out of a slurry of SWNT with poly (vinilydene difluoride) (PVDF) binder on to a Cu substrate, (2) evaporating SWNT dispersion in methanol on to a Cu substrate, and (3) transferring a film on to a Cu substrate from the water–ethanol interface, to prepare the working electrode for studying the Li ion insertion process. The use of binder enhances irreversible capacity restricting the Coulomb efficiency to only 18% in the initial cycle. The electrode prepared by deposition of SWNT powder from a dispersion of methanol on the Cu substrate gives the best reversible capacity of 445 mA h g⁻¹ and Coulomb efficiency of 25% in the initial cycle. Use of the PVDF binder favors the formation of thicker solid electrolyte interface, which counts the large irreversible capacity.     

二(乙酰丙酮根)合铜(Ⅱ)热分解动力学研究

金属有机化合物气相化学沉积(OMCTD)形成铜膜常用的母体化合物是铜(Ⅱ)的β-二酮类配合.本文首次采用CW二氧化碳激光研究二(乙酰丙酮根)合铜(Ⅱ)[Cu相似文献   

Incipient CdS thin film formation

The quality of a final thin film is essentially determined by the processes taking place at incipient CdS deposition, which in turn are strongly influenced by the physicochemical properties of the substrate and liquid in contact. SEM pictures of deposits formed through steady flow of a supersaturated (with respect to CdS) solution suggest that initially nuclei are continuously generated on the substrate and grow as discrete "surface" particles. With time, these particles tend to "coalesce" with neighboring ones, while new nuclei keep forming and growing, leading to the formation of a coherent film. There is evidence that similar growth patterns prevail in CdS deposition via the chemical bath deposition (CBD) process. Based on experimental observations, a simple model is developed, which is capable of predicting macroscopically determined film characteristics such as the temporal thickness evolution including the "induction period." Two cases of the growth pattern are examined theoretically; one based on instantaneous surface nucleation (due to its simplicity) and another with a constant surface nucleation rate, which appears to be closer to experimental observations.     

Self-assembled nanostructures on VSe2 surfaces induced by Cu deposition.

Analytical transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been applied for the characterization of evolution, lateral arrangements, orientations, and the microscopic nature of nanostructures formed during the early stages of ultrahigh vacuum electron beam evaporation of Cu onto surfaces of VSe2 layered crystals. Linear nanostructure of relatively large lateral dimension (100-500 nm) and networks of smaller nanostructures (lateral dimension: 15-30 nm; mesh sizes: 500-2000 nm) are subsequently formed on the substrate surfaces. Both types of nanostructures are not Cu nanowires but are composed of two strands of crystalline substrate material elevating above the substrate surface. For the large nanostructures a symmetric roof structure with an inclination angle of approximately 30 degrees with respect to the substrate surface could be deduced from detailed diffraction contrast experiments. In addition to the nanostructure networks a thin layer of a Cu-VSe2 intercalation phase of 3R polytype is observed at the substrate surface. A dense network of interface dislocations indicates that the phase formation is accompanied by in-plane strain. We present a model that explains the formation of large and small nanostructures as consequences of compressive layer strains that are relaxed by the formation of rooflike nanostructures, finally evolving into the observed networks with increasing deposition time. The dominating contributions to the compressive layer strains are considered to be an electronic charge transfer from the Cu adsorbate to the substrate and the formation of a Cu-VSe2 intercalation compound in a thin surface layer.     

Microstructural and auger microanalytical characterization of Cu-Hf and Cu-Ti catalysts.

Degradation processes occurring at the surface and in the bulk of Cu-based amorphous alloys during cathodic hydrogen charging were used for promoting the catalytic activity of such alloys. These processes modifying the structure, composition, and morphology of the substrate proved to be useful methods for transforming Cu-Hf and inactive Cu-Ti amorphous alloy precursors into active and durable catalysts. Indeed, their catalytic activity for dehydrogenation of 2-propanol increased up to a conversion level of approximately 60% at selectivities to acetone of about 99% for Cu-Ti and to conversion of approximately 90% at selectivities of approximately 95% for Cu-Hf. Previous attempts carried out by aging in air or hydrogen charging from the gas phase resulted in a maximum conversion level up to 15% for Cu-Hf and up to 3% for Cu-Ti. High resolution Auger spectroscopy allowed changes occurring during the activation process to be identified, namely, the formation of small Cu particles on the HfO2 surface and the formation of highly porous particles containing mostly Cu and some Ti and O (Cu-Ti-O) on a Cu-Ti substrate. Differences in the chemistry and structure of both catalysts are discussed, and the implications for catalytic function are considered. A probable configuration of active sites on the Cu-Ti-O/Ti-O-Cu catalyst for dehydrogenation of 2-propanol is proposed.     

Micropatterning of copper on a poly(ethylene terephthalate) substrate modified with a self-assembled monolayer

We have developed a technique for the site-selective electroless deposition of Cu on poly(ethylene terephthalate) (PET) substrate modified with an organic self-assembled monolayer (SAM). The PET substrate was first modified with a silica-like layer by being dip-coated in an acetone solution of 3-aminopropyltrimethoxysilane and treated with UV light. The PET substrate was further modified with thiol groups using a 3-mercaptopropyltrimethoxysilane-SAM and then irradiated by UV light through a photomask to prepare thiol-group regions and OH-group regions. Cu was then deposited on only the thiol-group regions of the substrate by electroless deposition in a neutral solution with no catalysts by using dimethylamineborane as a reducing reagent. This site-selective deposition process can control the deposition conditions by an organic thin film fabricated on a surface-modified PET substrate, and thus can be applied to other low heat-resistant substrates.     

Theoretical analysis of non-catalytic growth of nanorods on a substrate

A theoretical analysis explaining the whole process of the growth of nanorods on a substrate without a catalyst is presented. Prior to the growth of the nanorods, the reaction precursors form nuclei on the substrate. The nuclei undergo cluster migration caused by the surface diffusion of adatoms on the substrate, and this migration continues until the mean free time of the adatoms is larger than surface diffusion time. The most probable mechanism by which cluster migration takes place is the one that leads to the minimization of the cluster free-energy, namely the migration of six adatoms into one fixed adatom. This cluster migration continues during several (typically smaller than 6) consecutive nuclei growth steps. After the process of cluster migration comes to an end, the nuclei grow in an isotropic manner by collection of the adatoms, until the nucleus reaches the thermodynamic size limit. The one-dimensional growth of nanorods on the nuclei, which is associated with the critical radius, begins when the reactant dose is smaller than a certain value, which is determined by the thermodynamic size limit and the mass transport parameter. The mass transport of the reaction precursors leads to the expansion of the radius and elongation of the height of the nanorods, and the growth rate of the height is greater than that of the radius. This difference in the growth rate causes the aspect ratio to increase with increasing growth time. By comparing the experimental data in the literature (ZnO nanorods), the presented analysis explains well the noncatalytic growth of nanorods on a substrate.     

Chirality transfer from a single chiral molecule to 2D superstructures in alaninol on the Cu(100) surface

The formation of 2D chiral monolayers obtained by self-assembly of chiral molecules on surfaces has been widely reported in the literature. Control of chirality transfer from a single molecule to surface superstructures is a challenging and important aspect for tailoring the properties of 2D nanostructures. However, despite the wealth of investigations performed in recent years, how chiral transfer takes place on a large scale still remains an open question. In this paper we report a coupling of scanning tunneling microscopy and low energy electron diffraction measurements with an original theoretical approach, combining molecular dynamics and essential dynamics with density functional theory, to investigate self-assembled chiral structures formed when alaninol adsorbs on Cu(100). The peculiarity of this system is related to the formation of tetrameric molecular structures which constitute the building blocks of the self-assembled chiral monolayer. Such characteristics make alaninol/Cu(100) a good candidate to reveal chiral expression changes. We find that the deposition of alaninol enantiomers results in the formation of isolated tetramers that are aligned along the directions of the substrate at low coverage or when geometrical confinement prevents long-range order. Conversely, a rotation of 14° with respect to the Cu(100) unit vectors is observed when small clusters of tetramers are formed. An insight to the process leading to a 2D globally chiral surface has been obtained by monitoring molecular assemblies as they grow from the early stages of adsorption, suggesting that the distinctive orientation of the self-assembled monolayer originates from a balance of cooperating forces which start acting only when tetramers pack together to form small clusters.     

An observation of palladium membrane formation on a porous stainless steel substrate by electroless deposition

The membranes made of palladium and its alloys are used for the extraction of high quality hydrogen from a mixture of gases. Most of recent research is focused on the development technologies for depositing a durable ultra-thin palladium membrane on a porous substrate in order to assure a good mechanical support and maximize the flux of hydrogen permeation. The formation of a palladium membrane deposited on a porous stainless steel substrate by an electroless process is recorded and described in this paper. The palladium deposition progress around the pore area at the surface of the substrate in the initial stages is illustrated. A bridge model is presented to describe the membrane formation around the pore area of the substrate. This model, together with the micrographs showing the deposition progress on the pore areas, will lead to the control of the deposition process for a membrane fabrication as well as the design and modification of a substrate.