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排序方式: 共有10000条查询结果,搜索用时 203 毫秒
71.
M. D. Joseph Sebastian B. Rudraswamy M. C. Radhakrishna Ramani 《Bulletin of Materials Science》2003,26(5):509-515
Cobalt ferrite (CoxFe3?xO4) is prepared in powder form by thermal decomposition of iron and cobalt salts and is analysed by X-ray diffraction and Mössbauer spectroscopic techniques. The variation of Mössbauer parameters, lattice parameters and crystallite size of the products formed with variation in the composition of Fe and Co ratios are studied. The studies confirm the formation of nano-size cobalt ferrite particles with defect structure and it is found to be maximum for the Fe : Co = 60 : 40 ratio of the initial precursor oxides. 相似文献
72.
D. Faurie P.-O. Renault G. Patriarche E. Le Bourhis 《Surface & coatings technology》2006,201(7):4300-4304
The elastic behavior of supported gold thin films has been studied using a framework in which the elastic interaction between grains and the actual structure of the film (i.e. preferential grain orientation and grain shape) are taken into account. Experiments were carried out using synchrotron X-ray diffraction combined with in-situ tensile testing and thereafter, no assumptions on the residual stress state and on the stress-free lattice parameter a0 have to be made. Modeling of grain elastic interactions is based on the extension of Eshelby-Kröner model, which allows for estimating the elastic behavior of polycrystals considering the texture and the shape of the crystallites. Flat-disc shaped grains arrangement is shown to yield the best representation of the elastic behavior of the fiber-textured gold thin films composed of columnar grains. This non-intuitive representation results from free-surface effect. 相似文献
73.
The degradation behaviour of Kodar [poly(1,4-cyclohexylene dimethyl-eneterephthalate)] was investigated in air using thermogravimetry, differential thermal analysis and wide angle X-ray diffraction studies. The rates of crystallization and degradation were influenced by thermal exposure and polychromatic irradiation (Λ > 290 nm) for different time intervals. The crystallinity changes (Xc%) and activation energies (ΔE) for the systems have been determined. 相似文献
74.
多相物质粉末衍射的物相检索 总被引:1,自引:1,他引:0
余焜 《理化检验(物理分册)》2003,39(2):92-95
讨论了多相物质粉末衍射的物相检索问题,介绍了XRDS的物相检索软件。这是一种智能型的物相检索程序,考虑了测试数据的不确定度,以及粉末样品和块状样品衍射图谱各自的特点,不仅注意到实际样品中微量物相存在的可能,也注意到块状样品结构有序性的可能。XRDS能够帮助材料工作者同时检出样品中所含的多种物相及其含量,操作简单、结果可靠。 相似文献
75.
76.
S. Zaefferer 《Advanced Engineering Materials》2003,5(8):607-613
In recent years the investigation of local texture and microstructure by analysis of electron backscatter diffraction patterns (EBSP) in the SEM has become a very powerful and popular method. With the introduction of SEM with field emission guns (FEG) the spatial resolution of EBSP measurements could be enhanced from 500 nm with a tungsten emitter to better than 50 nm. This evolution of SEM techniques raises the question whether transmission electron microscopy (TEM) still has fields of application in texture research. The present article answers this question with a clear “yes” and presents three examples of investigations where TEM is indispensable. The three examples comprise the investigation of the correlation between dislocation structure and deformation texture, a study on nucleation mechanisms of recrystallization in highly deformed metals and the investigation of microtexture and microstructure in nanocrystalline materials. Together with the presentation of these cases some of the necessary measurement techniques are described briefly. It is shown that TEM has to be applied when highest spatial resolution of orientation determination and imaging and high accuracy of orientation determination are to be reached, when the three‐dimensional and quantitative characterization of lattice defects is required or when materials with a high density of lattice defects are to be investigated. 相似文献
77.
The selenisation of the thin film precursors indium, Cu-In and Cu-In-Ga has been studied by in-situ X-ray diffraction. The influence of sodium doping on the kinetics of the solid-state reactions observed agrees with the predictions derived from a phenomenological model presented earlier. In this model a layer of sodium polyselenide is assumed to form at the surface of the precursor, or around each crystal grain. This layer might be responsible for impeded ion exchange in certain solid-state reactions. 相似文献
78.
We have investigated synthesis conditions and some properties of sprayed Cu2ZnSnS4 (CZTS) thin films in order to determine the best preparation conditions for the realization of CZTS based photovoltaic solar cells. The thin films are made by means of spraying of aqueous solutions containing copper chloride, zinc chloride, tin chloride and thiourea on heated glass substrates at various temperatures. In order to optimize the synthesis conditions of the CZTS films, two series of experiments are performed. In the first series the sprayed duration was fixed at 30 min and in the second it is fixed at 60 min. In each series, the substrate temperature was changed from 553°K to 633°K. The X-ray diffraction shows, on one hand, that the best crystallinity was obtained for 613°K as substrate temperature and 60 min as sprayed duration. On the other hand, these CZTS films exhibit the kesterite structure with preferential orientation along the [112] direction. Atomical Force Microscopy was used to determine the grain sizes and the roughness of these CZTS thin film. After the annealing treatment, we estimated the optical band-gap energy of the CZTS thin film exhibiting the best crystallinity as 1.5 eV which is quite close to the optimum value for a solar cell. 相似文献
79.
The temperature programmed (palladium) hydride decomposition appeared very effective method for diagnosing the extent of alloying in Pd-Pt/SiO2 catalysts. Introduction of Pt to Pd catalysts moves the TPHD peak gradually towards lower temperatures and the shift in hydride decomposition peak is accompanied by a decrease in the amount of released hydrogen. The catalysts prepared the direct redox method showed much better alloy homogeneity than the samples prepared by coimpregnation. The results of probing with other techniques, i.e. catalytic probing with hydrodechlorination of CCl2F2 and XRD, were in line with TPHD data. The catalytic probing showed the presence of synergistic effect, a clear indication of Pd-Pt mixing. XRD data of post-reaction samples showed carbon incorporation into Pd-rich phase, whereas separate Pt-rich phase did not experience any bulk carbiding. 相似文献
80.
B. V. Korzoun L. A. Makovetskaya V. A. Savchuk V. A. Rubtsov G. P. Popelnyuk A. P. Chernyakova 《Journal of Electronic Materials》1995,24(7):903-906
Twenty alloys of various compositions in the Cu2Se-Al2Se3 system were prepared and investigated. The T(x) phase diagram of the Cu2Se-Al2Se3 system was obtained from x-ray diffraction, differential thermal analysis, and microstructure investigation for the first
time. The homogeneity region of the CuAlSe2 semiconducting compound was established.
Previous articles by this author were presented with the spelling of his name as B.V. Korzun. 相似文献