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1.
Thin films of nominal composition Ni-25at%Al have been sputter deposited from a target of the intermetallic compound Ni3Al at different substrate deposition temperatures. The film deposited on an unheated substrate exhibited a strongly textured columnar growth morphology and consisted of a mixture of metastable phases. Nanoindentation studies carried out on this film exhibited a strong strain hardening tendency. In contrast, the film deposited at 200 °C exhibited a recrystallized non-textured microstructure consisting of grains of a partially ordered Ni3Al phase. At higher deposition temperatures (∼400 °C), larger grains of the bulk equilibrium, long-range ordered, Ll2 Ni3Al phase were observed in the film. Unlike the film deposited on an unheated substrate, the films deposited at elevated temperatures did not exhibit any dependence of the hardness on the indentation depth and, consequently no strain hardening. The average hardness of the film deposited at 200 °C was higher than the one deposited at 400 °C. In addition to monolithic Ni-25Al thin films, multilayered Ni/Ni3Al thin films were also deposited. Multilayers deposited non-epitaxially on unheated substrates exhibited a strong {111} fiber texture while those deposited epitaxially on (001) NaCl exhibited a {001} texture. Free-standing multilayers of both types of preferred orientations as well as of different layer thicknesses were deformed in tension untill fracture. Interestingly, the {111} oriented multilayers failed primarily by a brittle fracture while the {001} multilayers exhibited features of ductile fracture.  相似文献   

2.
This paper presents the results of nanoindentation measurements of the hardness and moduli of normally and obliquely deposited nanocrystalline Ni films on substrates of SiO2, Si, and bulk Ni. Following an initial characterization of film microstructure and surface topography with atomic force microscopy (AFM), the paper examines the effects of film microstructure, film thickness, and substrate modulus on the measured film mechanical properties. Obliquely deposited films are shown to have lower hardness values than normally deposited films. The measured hardness values and material pile-up are also shown to depend significantly on the mismatch between the film modulus and substrate modulus. A framework is presented for quantifying the effects of substrate modulus mismatch on basic film mechanical properties.  相似文献   

3.
LiCoO2 thin films were fabricated by direct current magnetron sputtering method on STS304 and Ti substrates. The effects of substrate and annealing on their structural and electrochemical properties of LiCoO2 thin film cathode were studied. Crystal structures and surface morphologies of the deposited films were investigated by X-ray diffraction and field emission scanning electron microscopy. The as-deposited films on both substrates have amorphous structure. The (104) oriented perfect crystallization was obtained by annealing over 600 degrees C in STS304 substrate. The LiCoO2 thin film deposited on Ti substrate shows the (003) texture after annealing at 700 degrees C. The electrochemical properties were investigated by the cyclic voltammetry and charge-discharge measurement. The 600 degrees C-annealed LiCoO2 film deposited on STS304 substrate exhibits the inithial discharge capacity of 22 uAh/cm2 and the 96% capacity retention rate at 50th cycles. The electrochemical measurement on annealed films over 600 degrees C was impossible due to the formed TiO2 insulator layer using Ti substrate. As a result, it was found that the STS304 substrate seems to be more suitable material than the Ti substrate in fabricating LiCoO2 thin film cathode.  相似文献   

4.
通过直流溅射沉积法在玻璃衬底上制备了不同生长条件下的纳米金薄膜,利用X射线衍射(XRD)和原子力显微镜(AFM)对其进行表面形貌分析.XRD 图显示Au膜具有(111)面择优取向;AFM图显示,在不同的生长阶段Au膜具有不同的表面微结构.总结了不同的工艺条件对薄膜晶粒生长的影响,这项研究对实现金属薄膜的可控性生长有重要意义.  相似文献   

5.
The influence of annealing parameters on the martensitic phase transformation in sputter-deposited Ti rich Ni-Ti films is systematically studied by differential scanning calorimetry and by transmission electron microscopy. The annealing temperature range extends from the crystallization temperature of the films up to 900°C. For increasing temperature, multiple phase transformations, transformations via an R-phase or direct martensite/austenite transformations are observed. A similar behavior is found for increasing annealing time. Related changes of the film microstructure, such as the strongly varying distribution of round Ti2Ni precipitates in the grains, are analyzed. Transformation temperatures could be shifted over a wide range by adjusting the film composition from 48 to 54 at.% Ti. The corresponding transformation curves, grain structure as well as nature and amount of precipitates were investigated. No subsequent annealing process is required for films deposited on substrates heated above about 500°C. In this case, the as-deposited films have a very fine-grained and homogeneous microstructure.  相似文献   

6.
The effect of various substrate surface treatments on (i) the pre-growth topography and composition of the treated substrate, and (ii) the quality of diamond thin films produced by hot-filament chemical vapour deposition on tungsten carbide substrates, is reported. Two different substrate grain sizes were subjected to various surface treatments. They were then examined for surface material composition and topography using scanning electron microscopy and X-ray diffraction (XRD). Subsequently, diamond films were deposited on the samples and their quality analysed by Raman spectroscopy and XRD techniques. These analyses do not indicate a strong dependence between the substrate grain size and film quality. However, the surface-treatment method affects the resulting substrate surface topography and film quality. This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   

7.
Pure nickel thin films were deposited on Si (100) substrates under different conditions of sputtering using direct current magnetron sputtering from a nickel metal target. The different deposition parameters employed for this study are target power, argon gas pressure, substrate temperature and substrate-bias voltage. The films exhibited high density of void boundaries with reduction in <111> texture deposited under high argon gas pressures. At argon gas pressure of 5 mTorr and target power of 300 W, Ni deposition rate was ~40 nm/min. In addition, coalescence of grains accompanied with increase in the film texture was observed at high DC power. Ni films undergo morphological transition from continuous, dense void boundaries to microstructure free from voids as the substrate-bias voltage was increased from −10 to −90 V. Furthermore, as the substrate temperature was increased, the films revealed strong <111> fiber texture accompanied with near-equiaxed grain structure. Ni films deposited at 770 K showed the layer-by-layer film formation which lead to dense, continuous microstructure with increase in the grain size.  相似文献   

8.
运用sol-gel技术制备了(Pb,La,Ca)TiO3(简写为PLCT)铁电薄膜;利用XRD、SEM、AFM和EDAX分析了PLCT薄膜的结构、表面形貌和组分。XRD衍射结果表明,PLCT薄膜呈钙钛矿结构。随着退火时间的增加,PLCT薄膜的XRD衍射峰的强度也随之增加。SEM、AFM分析表明,PLCT铁电薄膜表面平整、致密、无裂缝。EDAX分析表明,PLCT薄膜的实际组分十分接近设计组分。利用PFM分析了PLCT薄膜的电畴结构,发现随着退火时间的增加,PLCT薄膜的电畴由细小圆点状逐渐增大并形成片状电畴。  相似文献   

9.
夏傲  黄剑锋  谈国强 《功能材料》2012,43(11):1403-1406
以硝酸铋和钛酸四丁酯为原料,以三氯十八烷基硅烷(OTS)为模板,采用自组装单层膜(self-as-sembled monolayers,SAMs)技术,在玻璃基板上成功制备了Bi2Ti2O7晶态薄膜。借助X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)、X射线能谱(EDS)及原子力显微镜(AFM)等测试手段对Bi2Ti2O7薄膜进行了表征。结果表明,以OTS为模板利用自组装技术,经540℃煅烧2h可成功制得立方相Bi2Ti2O7晶态薄膜,且薄膜表面平整光滑,均匀致密。  相似文献   

10.
T. I?ák  T. Daniš  M. Marton 《Vacuum》2007,82(2):134-137
This paper describes the influence of a co-catalyst on growth of carbon nanotubes (CNTs) by alcohol catalytic chemical vapour deposition (ACCVD) method. Silicon wafers covered with thermal oxide or polycrystalline diamond thin film were used as substrates. Ni thin film supported with Al, Cu or Ti was used as a catalyst. The films were deposited by pulsed laser deposition technique. Comparison of the various types of the co-catalyst (Al, Cu, Ti) leads to the conclusion that Cu co-catalyst is suitable for producing very thin single wall carbon nanotubes (SWCNTs) and combination of Al and Ni provide a good condition to the catalytic growth of CNTs. In addition, we observed also the influence of the various diffusion barriers (thermal oxide and polycrystalline diamond) on growth of CNTs. Prepared samples were analysed by Raman spectroscopy (RS) and scanning electron microscopy (SEM).  相似文献   

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