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采用沉淀转化法制备CuO的前驱体Cu(OH)2,对纳米CuO微晶的不同热分解条件下的样品进行了x射线衍射(XRD)实验研究。结合所获得的晶粒度和XRD微结构参数,发现纳米晶CuO的晶粒组元中存在着晶格畸变;随着温度的升高,纳米CuO晶粒长大且其微结构呈现出明显的变化,其晶格畸变与晶粒度有着比较密切的关系。 相似文献
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银钠米晶微结构的尺寸效应 总被引:2,自引:0,他引:2
对银纳米晶的系列样品进行了XRD微结构实验研究和计算。结合所得到的晶粒度和微结构参数发现纳米银晶粒组元中存在着晶格畸变;随着晶粒尺寸的变化,银钠米晶的微结构呈现出明显的变化,其晶格畸变与晶粒度有着比较密切的关系。 相似文献
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对银纳米晶的系列样品进行了XRD微结构实验研究和计算。结合所得到的晶粒度和微结构参数发现纳米银晶粒组元中存在着晶格畸变;随着晶粒尺寸的变化,银纳米晶的微结构呈现出明显的变化,其晶格畸变与晶粒度有着比较密切的关系。 相似文献
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对纳米MgO微晶的系列样品进行了差热分析测量和X射线衍射实验研究。结合所获得的晶粒度和XRD微结构参数,发现纳米晶MgO的晶粒组元中存在着晶格畸变;随着温度的升高,纳米MgO晶粒篚且其微结构呈现出明显的变化,其晶格畸变与晶粒度有着比密切的关系。 相似文献
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对γ相和α相纳米晶体Fe_2O_3的系列样品进行了X射线衍射点阵参量实验研究和计算。结合所得到的晶粒度和微结构参数,发现纳米晶体Fe_2O_3的晶粒组元中存在着晶格畸变;随着温度的升高,γ相和α相纳米晶体Fe_2O_3的点阵参量呈现出了明显的变化,其晶格畸变与晶粒度和温度有较密切的关联。 相似文献
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对γ相和α相纳米晶体Fe2O3的系列样品进行了X射线衍射点阵参量实验研究和计算。结合所得到的晶粒度和微结构参数,发现纳米晶体Fe2O3的晶粒组元中存在着晶格畸变;随着温度的升高,γ和α相纳米晶体Fe2O3的点阵参量呈现出了明显的变化,其晶格畸变与晶粒度和温度有较密切的关联。 相似文献
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借助精确的X射线衍射(XRD)测量,对不同晶粒度纳米锐钛矿相二氧化钛(n-A-TiO2)样品的晶粒微结构进行了细致研究,给出了标明晶面指数(hkl)和晶面间距dhkl值的系列XRD谱,并得到了晶面间距、晶格常数、轴比、晶胞体积等参数数值及其相对常规粗晶的变化情况,从而初步揭示出该样品晶粒微结构的尺寸效应.作者首次发现,纳米锐钛矿相二氧化钛样品中存在着非单调的备向异性晶格畸变. 相似文献
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锐钛矿TiO2纳米晶体的微结构尺寸效应 总被引:1,自引:0,他引:1
对制备条件相同、晶粒度不同的锐钛矿TiO2纳米晶体(n-A-TiO2)样品之晶粒微结构进行了细致的X射线衍射(XRD)研究,给出了标明晶面指数(hkl)和晶面间距(dhkl)值的系列XRD谱,并得到了晶面间距、晶格常数、轴比、晶胞体积等参数数值及其相对常规粗晶的变化情况,从而初步揭示出该样品晶粒微结构随粒度的变化情况。发现了锐钛矿TiO2纳米晶体样品中存在着单调的各向异性微结构尺寸效应。 相似文献
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对制备条件相同、晶粒度不同的锐钛矿TiO2 纳米晶体 (n A TiO2 )样品之晶粒微结构进行了细致的X射线衍射(XRD)研究 ,给出了标明晶面指数 (hkl)和晶面间距 (dhkl)值的系列XRD谱 ,并得到了晶面间距、晶格常数、轴比、晶胞体积等参数数值及其相对常规粗晶的变化情况 ,从而初步揭示出该样品晶粒微结构随粒度的变化情况。发现了锐钛矿TiO2 纳米晶体样品中存在着单调的各向异性微结构尺寸效应 相似文献
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The effects of monoethanolamine (MEA) and acetylacetone (ACAC) addition as stabilizer on the crystallization behaviour, morphology and optical properties of magnesium oxide were investigated using thermogravimetry (TG/DTG), X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Visible, photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy. Stabilizer addition reduces transparency of the films. MgO films prepared at 500 °C showed weak orientation of (200). However, the films prepared by addition of stabilizer are amorphous. MgO powders were prepared for exhibiting the structural properties. The patterns of MgO powders showed a preferred orientation of (200). The addition of stabilizer causes a reduction in grain size. SEM micrographs show that a homogenous and crack-free film can be prepared at 500 °C and addition of stabilizer causes an increase in packing density. 相似文献
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J. E. Alfonso M. Cardenas J. F. Marco 《Journal of Superconductivity and Novel Magnetism》2013,26(7):2463-2466
In this work MgO thin films have been grown onto common glass substrates by magnetron rf sputtering from a MgO (99.99%) target with dimensions of 4″×¼″. Basically, we found the optimum conditions for deposition such as working pressure (7×10?3 mbar), the power applied to the target (400 W) and the flow of Ar (20 sccm). The films have been characterized by X-ray diffraction (XRD) at a grazing angle at θ–2θ configuration, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and transmittance studies. The XRD results show that to reproduce the polycrystalline phase of the target, there is a power threshold of 250 W. AFM results indicate that the films present average roughness of the 200 Å and grain size of 1100 Å. XPS shows a surface composition of the films most external 5 nm, indicating the presence of MgO and Mg(OH)2. The optical characterization indicates that the films have a high absorption coefficient for wavelengths below 310 nm, and between 450 to 850 nm they showed a transmittance average of 90%. 相似文献
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采用阴极真空电弧离子沉积技术在玻璃及Si衬底上成功地制备了具有择优结晶取向的透明MgO薄膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)及紫外-可见吸收光谱仪分别对MgO薄膜微观结构、表面形貌及可见光透过率进行了测试与分析。XRD结果表明,所制备的MgO薄膜具有NaCl型立方结构的(100)、(110)和(111)3种结晶取向,在沉积气压为0.7~3.0Pa的范围内,薄膜的择优结晶取向随沉积气压的升高先由(100)转变为(110),最后变为(111)。SEM图表明随着沉积气压的升高,MgO薄膜的晶粒逐渐变小,薄膜结晶质量变差。在380~900nm范围内,沉积气压为0.7Pa下制备的MgO薄膜其可见光透过率高于90%,随着沉积气压的升高,薄膜的可见光透过率有所下降。 相似文献
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Mullite doped with MgO in quantities ranging from 0.01 to 1.5 wt% were prepared by the sol-gel method. The mullitization temperature decreases with increased MgO dopant content. The XRD patterns of the MgO-doped mullite calcined at temperatures up to 1600° C for durations ranging from 1 to 10 h did not show the presence of any other phase except mullite. The IR spectrum shows a broadening of the Al-O absorbance band at 1175cm–1 with MgO content, indicating the solid solution of MgO. Sintering temperature decreases with increased MgO dopant content. The microstructure observed consisted of equiaxed grains. The TEM observation of the microstructure showed the presence of glassy pockets at the triple grain junctions. The thermal coefficient of expansion and dielectric constant were not changed up to 0.75wt% MgO dopant concentration. The three-point bend strength observed for 0.3wt% MgO-doped mullite at room temperature was 300 MPa and decreased below 200 MPa at 1400° C. 相似文献
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The effectiveness of two kinds of magnesium oxide (MgO) materials, commercial MgO (2250 kg ha−1) and a material derived from MgO and magnesium silicate minerals named ‘MgO-SH-A’ (2250 and 4500 kg ha−11), in suppression of uptake and accumulation of cadmium (Cd) into grain of winter wheat (Triticum aestivum L. cv. Ayahikari) was examined in a Cd-contaminated alluvial paddy field under annual rice–wheat rotational system. The MgO materials were mixed into the plough-layer soil only once prior to the preceding rice cultivation. Cadmium concentration in wheat grain produced from the non-amendment control exceeded the maximum limit of Cd in wheat grain adopted by FAO/WHO (0.2 mg kg−1). All of the treatments with the MgO materials significantly lowered plant available Cd fraction in the plough-layer soil. However, only the treatment with the commercial MgO at 2250 kg ha−1 produced wheat grain whose Cd concentration was not only significantly lower than that from the control but also less than 0.2 mg kg−1. It is suggested that the significant suppressive effect of the commercial MgO on Cd accumulation in wheat grain would be mainly attributed to its high soil neutralizing capacity as compared to that of MgO-SH-A. 相似文献
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纳米TiO2粉晶的XRD研究 总被引:31,自引:5,他引:31
用溶胶-凝胶法制备了纳米TiO2粉晶,对不同温度自理的系列粉末用X射线衍射进行了研究,发现所得粉晶随热处理温度的不同发生了从锐钛矿到金红石相的转变。对系列粉晶进行了X射线衍射点阵参量计算,结合所得的晶粒度和微结构参数,发现纳米TiO2粉晶组元中存在着晶格畸变。 相似文献
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Percolated perpendicular FePt-MgO films with a (Fe48 Pt 52)100-x-(MgO)x/Pt(001)/Cr(002) structure were prepared by conventional dc magnetron sputtering (x=0-6.13). Magnetic measurements demonstrate that the coercivity of the magnetic film drastically increases from 169 to 285 kA/m as the MgO content is increased from 0 to 0.15 vol.%. However, the grain sizes of the FePt phase do not significantly varying upon doping with MgO. MgO does not appear at the grain boundaries of the FePt phase, but is present as crystalline dots that are uniformly precipitated in the FePt matrix. The MFM images revealed that the domain structure transformed from extending to isolate when the MgO dots precipitated into the FePt grains. Consequently, the MgO dots serve as pinning sites of the domain wall and enhance perpendicular coercivity. Percolated perpendicular magnetic recording is thus regarded as a solution to the problem of thermal instability in ultrasmall grains 相似文献