共查询到18条相似文献,搜索用时 78 毫秒
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C60/花生酸混合LB膜I.LB膜的X射线衍射和分子排列模型 总被引:3,自引:1,他引:2
制备了纯C60和C60/AA的混合LB膜。用X-射线衍射详细研究了它们的周期结构,表明C60分子在C60/AA混合LB膜中不是顶在花生酸疏水端头,而是包埋在花生酸分子之间,由此提出了一个新的分子排列模型。 相似文献
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由准稀溶液速冷凝胶(冻胶)化结晶方法制备出超高分子量聚乙烯(UHMWPE)膜。对不同成膜浓度条件,以及再经不同温度(室温~130℃)热处理后所获得的膜,用小角X射线衍射方法及广角X射线衍射仪对称反射几何布置,观测了它们的片晶层积状结构及其形态的变化。结果表明,这种C轴垂直于膜面的片晶层积状形态结构与初始成膜浓度有关。发现在可达最大拉伸比的成膜浓度范围(0.4~0.5g/100ml)内,膜中片晶排列 相似文献
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通过实例介绍运用高分辨X射线衍射分析技术对GaN异质外延薄膜材料的微结构进行研究,希望能获得不同缓冲层生长与优化工艺以及结构模型对其结构特性参数影响方面的信息,为GaN材料和器件制备者提供有用的参考。 相似文献
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利用近池数法对Co-Cr合金薄膜的衍射线性形进行分析,并提出用“三线法”确定衍射线的函数类型及其积分宽度,由此可计算薄膜的晶粒尺寸和微观应变。理论计算和实验表明,“三线 法”结合近似函数在线形分析方面是简便,可靠的。通过分析Co-Cr膜在不同工艺条件下(膜厚、Ar工作气体压强和负偏压)的衍射线线形,发现衍射线的物理展宽(即有效晶粒尺寸的减小)是粒取向度的下降是相应的,晶粒取向度的下降与结构缺陷密度 相似文献
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利用近似函数法对Co-Cr合金薄膜的衍射线线形进行分析,并提出用“三线法”确定衍射线的函数类型及其积分宽度,由此可计算薄膜的晶粒尺寸和微观应变。理论计算和实验表明,“三线法”结合近似函数法在线形分析方面是简便、可靠的。通过分析Co-Cr膜在不同工艺条件下(膜厚、Ar工作气体压强和负偏压)的衍射线线形,发现衍射线的物理展宽(即有效晶粒尺寸的减小)与晶粒取向度的下降是相对应的。晶粒取向度的下降与结构缺陷密度的增大有关。负偏压溅射时由于Ar原子残留在膜内引起晶格膨胀,从而使微观应变有较大增加。 相似文献
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利用离子束辅助沉积技术制备TaN薄膜,并对其进行X射线衍射分析。掠入射的X射线衍射分析得出:离子束辅助沉积制备的TaN薄膜是面心立方结构,晶格常数a为0.4405nm。根据X射线衍射分析,用屈服强度表征的TaN薄膜的显微硬度为16~20GPa,与文献上报道的显微硬度值接近。离子束辅助沉积制备的TaN薄膜宏观内应力较小,且都为压应力。晶粒尺寸大约在10nm左右,随着注入离子能量的增加,薄膜晶粒尺寸有长大的趋势。 相似文献
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首先采用真空蒸镀法制备了不同厚度的铜薄膜,并对薄膜进行了退火处理;然后用X射线衍射仪测定铜薄膜的衍射谱,最后采用线形分析法对衍射谱进行计算,得到了不同厚度铜薄膜退火前后的晶粒尺寸和微应变。结果表明:真空蒸镀铜薄膜晶粒尺寸随薄膜厚度的增加而增大,微应变随薄膜厚度的增加而减小;退火处理后薄膜晶粒明显长大,薄膜微应变在退火处理后明显减小。 相似文献
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J.Bashir R.T.A.Khan T.Ikeda KenichiOhshima 《材料科学技术学报》2003,19(2):189-190
Thermal parameters of TIBr were determined using both X-ray and neutron diffraction techniques. The data was analysed by Rietveld profile refinement procedure. From the neutron diffraction data, due to weak odd-order reflections, it was not possible to determine the individual thermal parameters. The X-ray diffraction measurements yielded BT1=0.296(5)nm2 and BBr=0.162(5) nm2. The overall isotropic value, J9 was 0.252(7) nm2 which is in good agreement with B=0.230(8) nm2 obtained from present neutron diffraction measurements. The present values are also in good agreement with theoretical estimates obtained from the shell models. 相似文献
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Ji Zhenguo Lu Huanming Zhang Shiguo Que Duanlin Usami N. Sunamura H. Shiraki Y. 《Journal of Materials Synthesis and Processing》1999,7(3):205-207
Pure-Ge/Si short-period superlattice (SPS) samples consisting of 1.5-monolayer Ge and a 1.4- to 3.8-nm-thick Si layer grown by gas source molecular beam epitaxy (GS-MBE) were studied by double-crystal x-ray diffraction. For SPS with a Si layer less than 2.4 nm, the satellite peak caused by the SPS structure in the rocking curve is quite broad, and no fine structure is found, indicating that there exists dislocation and waviness epilayers in the SPS. For SPS with a thick Si layer, the rocking curve is sharp and fine interference structures exist, indicating smooth epilayers in the SPS. It is found that both broad and sharp peaks exist but without fine structure in the rocking curves for SPS samples with a Si layer thickness (L
Si) in the range of 2.1–2.9 nm, which is the range in which an abnormal photoluminescence band appears in photoluminescence spectra. This result strongly supports H. Sunamura's suggestion that the abnormal photoluminescence band is caused by waviness formation of the epilayer due to vertical correlation of thickness fluctuations by the local strain field. 相似文献
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Haruhiko Suzuki Yun Xue Akiko Hosomichi Shumsun Naher Fumiaki Hata Hiroshi Kaneko 《Journal of Superconductivity and Novel Magnetism》2006,19(1-2):89-94
By using an ultra-low temperature X-ray diffractometer, we studied low temperature phase transitions of several materials.
These phase transitions are classified into a ferro quadrupole ordered phase, that is, Jahn–Teller distortion (TmVO, ZnCrO), an antiferro quadrupole ordered phase (CeB, PrPb), and a superconducrivity (MgB). We also investigated unknown phases, such as the low temperature phase in PrPtBi and the 4th phase in CeLaB. Our low temperature X-ray measurement gives rise to a fruitful information about the phase transition. Not only a whole
profile of the reflection peaks, which can be analyzed by the Rietveld method, we also made the precise measurement of the
temperature dependence of the integrated intensity of the reflection peak, the full width at half maximum, and the lattice
spacing for some fixed reflections. The temperature dependence of the integrated intensity (I.I.) can be expressed by the
Debye–Waller expression. At low temperatures, the change of the phonon frequency can be obtained from the I.I. through the
Debye–Waller factor. In MgB we observed the hardening of the phonon and the softening of phonon above and below the superconducting transition temperature,
respsctively. This result suggests the relevant mechanisim of superconductivity in MgB is the electron–phonon interaction. From the precise measurement of the lattice constant, we found the negative thermal expansion
at low temperatures in many correlated electron system. This negative thermal expansion can be explained by the Fermi liquid
theory by Misawa. 相似文献
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J. M. Ll cer V. Gallardo R. Delgado J. P rraga D. Martin M. A. Ruiz 《Drug development and industrial pharmacy》2001,27(9):899-908
Using different techniques, we studied the possible formation of ondansetron polymorphs. Ondansetron is a carbazol antiemetic that acts as a competitive, selective inhibitor of 5-HT3 serotonin receptors. The polymorphs were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results suggest that the compounds are not true crystallographic polymorphs, but instead are the product of physical structural changes in the drug, which would be of interest pharmaceutically. 相似文献