碳污染对钛膜吸氢能力影响的研究

在钼基底上蒸镀钛膜，用乙炔在钛膜表面引入碳污染，用Ｘ射线光电子谱和俄歇电子谱研究钛膜表面的碳的化学状态，以及表面的碳污染对钛吸氢能力的影响。实验发现，碳在钛表面以二种到三种化学状态存在。碳在钛表面将使钛膜的吸氢能力下降，而且不同化学状态的碳对钛膜吸氢能力的影响也不同。实验结果表明，呈ＴｉＣ状态的碳是降低钛膜吸氢能力的主要因素，共原因是它使解离吸附位置减少。     

钯对钛膜吸氢能力的抗污染作用的研究

为寻求一种防止因表面污染而导致钛膜吸氢能力下降的的途径，用表面分析方法检测样品表面状态，用质谱仪测量样品吸氢能力，研究了表面状态和吸氢能力的相互关系。采用在钛膜上淀积钯膜的方法，可使受碳，氧污染的钛膜吸氢能力得以恢复。这种钯／太复合结构在吸氢有力上对碳，氧污染并不灵敏     

钯对钛膜吸氢能力的抗污染作用的研究

为寻求一种防止因表面污染而导致钛膜吸氢能力下降的途径，用表面分析方法检测样品表面状态，用质谱仪测量样品吸氧能力，研究了表面状态和吸氢能力的相互关系。采用在钛膜上淀积钯膜（蒸发或溅射）的方法，可使受碳、氧污染的钛膜吸氢能力得以恢复。这种钯／钛复合结构在吸氢能力上对碳、氧污染并不灵敏。对样品的近费米能级处的占有电子态密度（densityofstate，DOS）的测量证明，凡吸氢能力良好的样品，DOS呈峰形结构。具有抗污染能力的钯／钛结构，其DOS因污染而导致的变化很小，而无抗污染能力的钛膜，其峰形结构受污染作用而消失。这种峰形结构能提供氢分子解离吸附过程中所需的电子。     

表面氧污染影响钛膜吸氢量的机理

表面氧污染的钛膜，其吸氢能力比清洁钛膜降低达数倍之多。在厚度d为40nm，表面氧污染的钛膜表面上，重新蒸镀一层极薄的（约1．2nm）清洁钛膜，吸氢、释氢的测量表明其吸氢能力得到恢复。另外，还对其他四块不同厚度的钛膜，在表面清洁及氧污染的条件下，分别进行了吸氢能力实验。实验结果证实：氧污染降低钛膜吸氢能力的原因是使钛膜上氢分子解离的位置减少，而不是扩散阻挡层的作用。     

表面氧污染影响钛膜吸氢量的机理

表面氧污染的钛膜，其吸氢能力比清洁钛膜降低达数倍之多，在厚度ｄ为４０ｎｍ，表面氧污染的钛膜表面上，重新蒸镀一层极薄的（约１．２ｎｍ）清洁钛膜，吸氢，释氢的测量表明其吸氢能力得到恢复。另外，还对其他四块不同厚度的钛膜，在表面清洁及氧污染的条件下，分别进行了吸氢能力实验，实验结果证实，氧污染降低钛氢能力的原因是使钛膜土氢分子解离的位置减少，而不是扩散阻挡层的作用。     

钛膜吸氢与释氢特性的研究

在SKL－12型多功能谱仪的预处理室中，采用超高真空镀膜的方法，得到了表面清洁的钛膜。对表面清洁及有一定量氧污染的钛膜进行了吸氢、释氢实验，并用理论模型拟合实验数据。结果表明：表面氧污染使钛膜吸氢能力降低，其原因在于氧原子占据了钛膜表面的吸附位置，使氢解离为原子的几率降低。     

钛膜吸氢与释氢特性的研究

在ＳＫＬ－１２型多功能谱仪的预处理室中，采用超高真空镀膜的方法，得到了表面清洁的钛膜。对表面清洁及表面一定量氧污染的钛膜进行了吸氢，释氢实验，并用理论模型拟合实验数据。结果表明：表面氧污染使钛膜吸氢能力降低，其原因在于氧原子占据了钛膜表面的吸附位置，使Ｈ２解离为原子的几率降低。     

钛膜吸氢与释氢特性的研究

在ＳＫＬ－１２型多功能谱仪的预处理室中，采用超高真空镀膜的方法，得到了表面清洁的钛膜。对表面清洁及有一定量氧污染的钛膜进行了吸氢、释氢实验，并用理论模型拟合实验数据。结果表明：表面氧污染使太膜吸氢能力降低，其原因在于氧原子占据了钛膜表面的吸附位置，使氢解离为原子的几率降低。     

表面氧污染影响钛膜吸氢量的机理

表面氧污染的钛膜，其吸氢能力比清洁钛膜降低达数倍之多。在厚度ｄ＝４００Ａ，表面氧污染的钛膜上重新蒸镀，使其表面再生一层极薄的清洁钛膜。吸氢，释氢测量表明其吸氢能力得到恢复。     

氧等离子体处理对氧化铟锡表面化学状态影响的ADXPS研究

利用变角X射线光电子谱对氧等离子体处理前后氧化铟锡ITO薄膜的表面化学状态进行了表征.实验发现用溶剂清洗之后的ITO薄膜表面存在一层厚度大约为0.7nm的非导电碳氢化合物污染层.氧等离子体处理方法可有效地消除C污染,而残存的少量污染C被部分氧化形成含羰基和羧基的化学物种.氧等离子体处理不仅提高了约5.0nm深度范围内的ITO薄膜表层中O的总体含量,更重要的是提高了膜层中O2-离子氧种的含量,改变了膜层化学结构,使得ITO薄膜表面的导电性能降低,同时改善了整个表面层化学结构的均匀性.     

GCr15钢等离子体基离子注入Ti和C混合层的XPS研究

用X射线光电子谱研究了GCr15轴承钢不平衡磁控溅射沉积Ti,继之等离子体基离子注入碳的等离子体基离子注入混合层的C ,Ti浓度深度分布及其化学结构。表明混合层的最表层为碳沉积层 ,其C 1s谱峰呈类金刚石特征 ,喇曼光谱肯定了这一特征。碳沉积层下面为C Ti混合区 ,Ti和C各以游离态和化合物态存在。混合层内Ti和C浓度沿层深连续变化 ,无突变区 ,在原Ti沉积层与基材轴承钢发生反冲增强扩散现象     

Gas permeation study of Ti-coated, track-etched polymeric membranes

The track-etched polymeric membranes have higher permeability for hydrogen as well as carbon dioxide. In present work, we have deposited thin film of Ti having thickness 100-150 nm on polymer membrane surface using vacuum evaporation method under 10⁻⁶ Torr for filling the tracks by the Ti metal. The gas permeability of Ti-deposited membrane is modified because Ti has close affinity for hydrogen. The samples are characterized by UV-vis spectroscopy and optical microscopy. The Ti-coated, track-etched membranes are applicable for relatively higher permeation for hydrogen as well as higher selectivity and also these are technologically important for purification of hydrogen.     

(Ti,Al)N薄膜的升温出气特性研究

介绍了采用多弧离子镀方法在不锈钢表面镀覆(Ti,Al)N薄膜,并对膜的结构、表面成分和形貌进行了简单分析,用热出气方法研究其出气特性,并与不锈钢的热出气性能进行比较,发现在不锈钢表面镀覆一层(Ti,Al)N膜可以有效地阻挡不锈钢体内氢扩散和碳偏析,因此(Ti,Al)N是比较理想的真空材料。     

Effect of carbon addition on activation and hydrogen sorption characteristics of TiMn1.25Cr0.25 alloy

Effect of carbon addition on activation and hydrogen sorption characteristics of TiMn_1.25Cr_0.25 alloy is investigated. With increasing carbon contents, the lattice constants and the unit cell volume decrease. The activation of TiMn_1.25Cr_0.25 alloy becomes easier with the increasing carbon content. Auger electron spectroscopy (AES) results show that carbon addition does not reduce the thickness of oxide layer formed on the surface of TiMn_1.25Cr_0.25 alloy, but makes the Ti/Mn ratio of alloy top surface become closer to the bulk components, which probably is one of the reasons for the improvement of alloy activation performance. Pressure–composition–temperature (PCT) results present that carbon addition decreases hydrogen absorption capacity and increases the hydrogen absorption–desorption plateau pressure. In addition, the cycle-life of hydrogen absorption–desorption increases with increasing carbon concentration.     

双辉等离子表面冶金技术的新进展

总结了近年来双层辉光离子渗金属技术的发展，介绍了以双辉工艺在钛及钛合金表面形成阻燃合金，采用无氢渗碳在钛及钛合金表面形成高硬抗磨层，在纯铁、碳钢等基材表面形成时效硬化高速钢，在纯铜表面形成Ti-Cu耐磨合金等表面冶金新技术。     

A comparative study of the impurity segregation from commercially pure Ti, Ti6Al4V and Ti3Al8V6Cr4Zr4Mo

The surface composition of commercially pure Ti, Ti6Al4V and Ti3Al8V6Cr4Zr4Mo during annealing at different constant temperatures was experimentally investigated. Auger electron spectroscopy was used to monitor the APPHs of the specified elements present on the surfaces. The surfaces of Ti and its alloys were contaminated by oxygen and carbon, and the contamination is attributed to the continual uptake of the background gases, even in the UHV chamber. It was found that mainly C and S segregated at 400 °C, and Cl at higher temperatures (500–630 °C) for commercially pure Ti. However, S was the main segregating species for all three samples. The segregation of Al was measured for the Ti6Al4V and Ti3Al8V6Cr4Zr4Mo samples at higher temperatures. The linear least-square fit method was employed to determine the contribution of pure Ti and TiC from the measured APPH's. The AES fitting confirmed the formation of TiC on the surface at temperatures 400–500 °C.     

Effects of carbon nanotubes and metal catalysts on hydrogen storage in magnesium nanocomposites

This paper reports a study on nanostructured magnesium composites with carbon nanotubes (CNTs) and catalytic transition metals with high H2 adsorption capacity and fast adsorption kinetics at reduced hydrogenation temperatures. Nanostructures in such a composite are shown to be responsible for improvements in both adsorption capacity and kinetics. It is found that the carbon nanotubes significantly increase the hydrogen storage capacity, and the catalytic transition metals (Fe and Ti) greatly improve the kinetics. This could be understood from the enhancement of diffusion by CNTs and decrease in energy barrier of hydrogen dissociation at the magnesium surface.     

Hydrogen Storage in Carbon-Based Nanostructured Materials

Carbon nanostructures represent a revolution in science and hold the potential for a large range of applications because of their interesting electrical, mechanical, and optical properties. Multiwall carbon nanotubes and carbon nanofibers of herringbone formation were grown by chemical vapor deposition on different catalysts from a number of hydrocarbon sources. After the total or particle removal of the catalyst system, the carbon nanostructures were analyzed for hydrogen uptake. Six samples of nanofibers grown on a Pd-based catalyst system (with a surface area of 425–455 m²/g) were controlled oxidized in air, such that they had different ratios of Pd/C varying from 0.05 to 0.9 mole ratio. The hydrogen uptake experiments were performed volumetrically in a Sievert-type installation and showed that the quantity of desorbed hydrogen (for pressure intervals ranging from 1 to 100 bars) by the carbon nanostructures free of any metal catalyst particles was between 0.04 and 0.33% by weight. For the samples of nanofibers that contained Pd in various Pd/C ratios, palladium revealed catalytic properties and supplied atomic hydrogen at the Pd/C interface by dissociating the H₂ molecules. The results show a direct correlation between the Pd/C ratio and the quantity of hydrogen absorbed by these samples. A saturation value of about 1.5 wt.% was reached for a high ratio of about 1:1 of Pd/C. The multiwall carbon nanotubes grown on a Fe:Co:CaCO₃ catalytic system and purified by acid cleaning and air oxidation showed a hydrogen uptake value of 0.1 to 0.2 wt.%.