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。     

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。     

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。     

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。     

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。     

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（C2H2）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膜吸氢能力的影响。实验发现，碳在钛表面以两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，其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。     

贮氢材料TiFeMm中毒与再生的研究

本文概括叙述了贮氢材料TiFeMm的贮氢特性及其表面中毒与再生机制。在贮氢材料TiFe中添加少量混合稀土金属Mm,改善了它的活化条件。我们发现,当使用98％工业纯氢气吸氢时,由于表面中毒,贮氢量下降。第一个吸放氢循环,其吸氢量下降约23％;第三个循环,其下降约61％。尽管如此,TiFeMm的抗毒性能还是比TiFe要好。中毒后的TiFeMm,经三次纯氢循环再生后,贮氢容量可回升到96％。由UPS分析表明,TiFeMm表面上过渡金属铁的d带峰强度是预测催化性质的重要依据。从AES、XPS分析结果指出,TiFeMm表面上的钛与铁分别呈TiO和金属态铁,还有少量氧与碳的表面污染。很明显,表面中毒以后,分别形成TiO_2和Fe_3O_4的表面化合物,从而抑制氢分子H_2→2H催化分裂和氢的渗透,致使贮氢量下降。从应用观点出发,我们相信,试验结果对于类似贮氢材料是很重要的。     

Influence of substrate properties on the growth of titanium films: Part II

In situ internal stress measurements were used to investigate the influence of the chemical properties of the substrate on the growth of a titanium film deposited under UHV conditions. The substrate films used were titanium films evaporated at different water partial pressures. When the titanium film is evaporated at substrate temperatures of 130 °C and higher the shape of the stress vs thickness curve is interpreted to indicate island growth. Comparing the internal stress curve of titanium on Al₂O₃ and Ti/H₂O substrates it is seen that the initial tensile stress is significantly larger on the Ti/H₂O substrate film. This larger tensile stress is interpreted to originate from a redistribution of oxygen at the substrate interface during the early growth stage of the clean titanium film. A compressive stress contribution at higher thickness of the titanium film is interpreted to be due to hydrogen interdiffusion from the substrate into the titanium film. Annealing of the Ti/H₂O substrate films at 350 °C for 20 min reduces the concentration of the surface oxygen species and the amount of hydrogen incorporated in the films.

Dosing of previously annealed Ti/H₂O substrate films with water affects both the oxygen concentration on the surface of these substrate films and the amount of hydrogen incorporated in the films. Oxygen dosing of these films only increases the concentration of the oxygen species on the substrate surface; thus only the initial tensile stress built up in the titanium film is affected. Dosing the films with hydrogen, on the other hand, only increases the amount of hydrogen incorporated in the substrate film, which by way of interdiffusion into the growing titanium film gives rise to a larger compressive stress at higher film thickness     

Rapid erasing of wettability patterns based on TiO2-PDMS composite films

TiO₂-polydimethylsiloxane (TiO₂-PDMS) composite films are prepared using the sol–gel method from a Ti(OBu)₄–benzoylacetone solution containing PDMS. The prepared films are cured by irradiation with ultraviolet (UV) light. Structural changes in the films after UV irradiation are confirmed by UV–vis absorption experiments, which show that an absorption band characteristic of the benzoylacetonate chelate rings disappears. This finding is ascribed to structural changes associated with the dissociation of the chelate rings. The IR spectra of the thin films exhibit a broad absorption band after UV irradiation, indicating that a Ti–O–Ti network forms in the thin film. Contact angles are measured for the TiO₂-PDMS thin films, showing wettability conversion from hydrophobic to superhydrophilic states by irradiation with oxygen plasma for 1 s. This phenomenon is explained by XPS experiments which reveal that the number of carbon atoms decreases, whereas the number of oxygen atoms increases on the surface of the TiO₂-PDMS composite films. Finally, hydrophobic–superhydrophilic patterns are fabricated based on a patterned TiO₂-PDMS composite film. The film displays a rapid change to superhydrophilicity over the whole film surface upon plasma irradiation for 1 s, which means that the wettability patterns are rapidly erasable.     

离子束辅助沉积制备TiO_2-Nb_2O_5氧敏薄膜

采用离子束辅助沉积方法在Ａｌ２Ｏ３陶瓷衬底上制备了ＴｉＯ２Ｎｂ２Ｏ５氧敏薄膜。考察了薄膜组分比及退火温度对薄膜氧敏特性和结构的影响。电阻氧分压特性测试结果表明，纯Ｎｂ２Ｏ５薄膜的氧敏特性优于纯ＴｉＯ２薄膜；掺入少量的Ｔｉ可使Ｎｂ２Ｏ５薄膜的氧敏特性提高，以５ｍｏｌ％ＴｉＯ２掺杂的Ｎｂ２Ｏ５薄膜最佳；过量掺杂则使Ｎｂ２Ｏ５薄膜的氧敏特性明显变差。在５ｍｏｌ％ＴｉＯ２Ｎｂ２Ｏ５薄膜中再掺入少量的Ｐｔ（０３％０５％）可使其氧敏特性更好，而且其响应时间大大缩短。Ｘ射线衍射谱（ＸＲＤ）和Ｘ射线光电子谱（ＸＰＳ）分析表明，在退火后的ＴｉＯ２Ｎｂ２Ｏ５薄膜中Ｎｂ２Ｏ５为单斜（Ｍｆｏｒｍ）结晶相，而掺杂的Ｔｉ以非晶的ＴｉＯ２形式存在，即使在高达３４ｍｏｌ％ＴｉＯ２Ｎｂ２Ｏ５薄膜中也不例外。纯ＴｉＯ２膜为金红石结构。不同退火温度（９００１１０００Ｃ）对薄膜的氧敏特性和结构无明显影响。     

磁控溅射制备掺银TiO2薄膜的光催化特性研究

利用交流磁控溅射设备采用金属Ti靶在石英和硅衬底制备掺银TiO2薄膜,并利用SEM,XRD及吸收光谱等方法分析测试TiO2薄膜的性质,探讨了掺银对TiO2薄膜吸收光谱的影响.并通过对甲基橙溶液浓度变化研究了掺银TiO2薄膜光催化特性,分析了掺银对TiO2薄膜增强光催化作用的工作机理,研究结果表明掺银有利于TiO2薄膜对有机物的降解作用.     

MOD制备的PZT薄膜的相结构发展和成分分析

采用MOD工艺制备了PZT薄膜,利用XRD和TEM研究了焦绿石相向钙钛矿相的转变过程．制备在Pt／Ti／SiO₂／Si衬底上的PZT薄膜,其XRD分析显示焦绿石相在600℃完全转变为钙钛矿相;与之相比,Pt箔上无支持的PZT薄膜,其TBM分析表明PZT焦绿石相完全转变为钙钛矿相的温度更高,且与薄膜的厚度有关．XPS研究表明,薄膜表面含有化学吸附氧和污染碳,无其它杂质存在.表面富含少量Pb,其Zr／Ti比与化学计量比一致,但晶格中缺氧．     

Electrical and optical properties of reactive sputtered TiO x thin films for uncooled IR detector applications

Nanostructured titanium oxide (nano-TiO _x ) thin films for uncooled IR detectors were fabricated by dc reactive magnetron sputtering and post-deposition annealed in oxygen atmosphere. The crystalline structure and surface morphology were characterized by glancing incidence X-ray diffraction (GIXRD) and field emission scanning microscopy. The results of GIXRD measurements indicate that TiO _x thin film deposited at room temperature is amorphous. A mixture of anatase and rutile nanocrystalline structure phase were present in oxygen annealed TiO _x thin film. A weak absorption peak around 438 cm^?1 corresponding to Ti–O stretching vibration is observed by Fourier transform infrared spectroscopy with annealed TiO _x thin film. The X-ray photoelectron spectra reveals Ti³⁺ and Ti⁴⁺ ions are coexisting in TiO _x films. The optical spectra of the films indicate that the optical absorption edge of the nano-TiO _x film exhibits a red shift compared to the as-deposited film. Furthermore, compared to bulk TiO _x , a blue shift was observed in both of the deposited and annealed films due to quantum size effect. The dependence of resistivity on temperature reveals both the absolute value of temperature coefficient of resistivity (TCR) and activation energy of TiO _x thin film increase significantly after annealing in oxygen.     

Fabrication of micro-patterned TiO2 thin films incorporating Ag nanoparticles

A photosensitive TiO₂ thin film embedded with Ag nanoparticles has been prepared from a Ti(OBu)₄–acetylacetone solution, containing dispersed Ag nanoparticles, by the sol–gel method. UV–visible absorption spectra showed that the thin film obtained has two absorption bands, characteristic of the acetylacetone chelate rings and plasmon resonance from Ag nanoparticles. After the irradiation of UV light, the absorption band from the chelate rings almost disappeared, ascribed to structural changes associated with dissociation of the chelate rings. The thin film after the UV irradiation exhibited a broad absorption band in the IR spectrum, indicating that a Ti–O–Ti network was formed in the thin film. HRTEM and EDX spectra revealed that Ag nanoparticles were present and dispersed in the TiO₂ thin film. Micro-patterns of 50 μm dots have been fabricated by UV irradiation through a corresponding photomask, followed by leaching.