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固-固化学法制备Ce0.75Zr0.25O2氧化物固溶体及其表征 总被引:1,自引:0,他引:1
以碳酸铈、氯氧锆和草酸为原料,采用机械力活化固-固化学法制得前驱物,前驱物经热分解获得了相应的目标产物Ce0.75Zr0.25O2氧化物固溶体.对前驱体进行了热重-差热(TG-DTA)测试,分析了在球磨及煅烧过程中可能发生的化学反应.采用X-射线衍射(XRD),透射电镜(TEM)和光电子能谱(XPS)等对产物进行了表征,实验结果表明:产物为单一的立方晶系固溶体,没有单独的氧化锆或氧化铈存在,粉体分散性好,呈圆球状,分布均匀,平均粒径为15.8 nm,比表面积达85.4 m2/g.对机械力活化固相化学反应的机制进行了研究. 相似文献
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在240℃水热体系中首次合成出系列纳米晶固溶体(CeO2)1-x(BiO1.5)x(x=0.0~0.50).产物采用X射线衍射,扫描电子显微镜和X射线光电子能谱仪进行表征.Bi2O3在CeO2中的固溶限约为50%.所有固溶体结晶属立方萤石结构,粒度范围为10~18nm.当Bi2O3掺杂量小于固溶限时,于800℃烧结不会导致结构转变.而对于(CeO2)0.5(BiO1.5)0.5,于800℃在空气中烧结将导致固溶限降低.Bi2O3含量低于固溶限时,固溶体只具有体电导,而(CeO2)0.6(BiO1.5)0.4的总电导可分为体电导和晶界电导.体电导为氧离子,而晶界为来自电极的银离子. 相似文献
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用X射线衍射法测定了Sm2O3-CeO2-CuO三元系固线下相关系,样品是在空气气氛1000℃烧结的。该体系含有一个三元固溶体Sm2-xCexCuO4-y,2个三相共存区和3个两相共存区,测定Sm2-xCexCuO4-y固溶体的固溶限、氧含量和超导电性,讨论了晶体结构和氧含量对超导电性的影响。 相似文献
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Xue-Ping Zhang Wen-Yao Zhang Dan Wang Hai Zhang Shi-Hua Sang 《Russian Journal of Inorganic Chemistry》2017,62(7):995-1002
In this work, the solubilities of the salt minerals and the densities of solution in two ternary systems sodium chloride–zinc chloride–water and magnesium chloride–zinc chloride–water were measured at 373 K using an isothermal solution saturation method. Based on the determined equilibrium solubility data and the corresponding equilibrium solid phase, the phase diagrams and density diagrams of the two systems were plotted. The results show that the two ternary systems are complex and the eutectic points, the univariant solubility curves and the solid crystalline phase regions are shown and discussed. The phase diagram of the ternary system NaCl?ZnCl2?H2O at 373 K is constituted of two eutectic points, three univariant solubility curves and three solid crystalline phase regions corresponding to NaCl, ZnCl2 and 2NaCl · ZnCl2. And the phase diagram of the ternary system MgCl2?ZnCl2?H2O at 373 K includes two eutectic points, three univariant solubility curves and three solid crystalline phase regions corresponding to MgCl2 · 6H2O, MgCl2 · ZnCl2 · 5H2O and ZnCl2. The experimental results were simply discussed. 相似文献
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The phase equilibria of quaternary system NaCl-NaBr-Na2B4O7-H2O at 348 K were studied by the isothermal equilibrium method. The solubilities and densities of the equilibrium solution were determined. According to the experimental data, the phase diagram, density-composition diagrams and water content diagram of the quaternary system at 348 K were plotted respectively. And the phase diagram consists of one univariant curve, two crystallization fields and without any invariant point of the quaternary system. The equilibrium solid phases of the two crysta- llization fields were Na(Cl, Br) and Na2B4O7·5H2O. The experimental results show that the quaternary system contained solid solution. The densities of the solution decrease with increasing NaCl concentration and increase with increasing NaBr concentration. 相似文献
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用一步合成法对CsxRb1-xYbI3体系进行了全组成范围内的合成,采用差热分析和X射线粉末相分析法制作了相图,用体系的荧光光谱进一步验证了相图的可靠性.该体系形成一个既有包晶反应又有类低共熔反应的有限固溶体,包晶反应温度和类低共熔反应温度分别为627℃和371℃.相分析确定了RbYbI3高温相及三类固溶体的结构:0≤x≤0.5形成以RbYbI3为基的NH4CdCl3型固溶体和以RbYbI3高温相为基的CaIrO3型固溶体,0.75≤x≤1.0形成以CsYbI3为基的GdFeO3型固溶体. 相似文献
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Self-propagating high-temperature synthesis of intermetallic compounds is of wide interest. We consider reactions in a binary system in which the rise and fall of the temperature during the reaction is such that one of the reacting metals melts but not the other. For such a system, using the phase diagram of the binary system, we present a general theory that describes the reaction taking place in a single solid particle of one component surrounded by the melt of the second component. The theory gives us a set of kinetic equations that describe the propagation of the phase interfaces in the solid particle and the change in composition of the melt that surrounds it. In this article, we derive a set of equations for one- and two-layer systems in which each layer is a binary compound in the phase diagram. The system of equations is numerically solved for Al-Ni to illustrate the applicability of the theory. The method presented here is general and, depending on the complexity of the phase diagram, it could be used to obtain similar equations for systems with more layers. 相似文献
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运用浓度比较法, 对25 ℃时V-H2O体系进行热力学分析和电化学分析, 编程计算出各溶解组分浓度, 以及固相和液相、各固相间边界线, 确定固相区和液相区的位置. 在此基础上, 绘制出了总V浓度cT(V)=1.0×10-5 mol·L-1时V-H2O体系的溶解组分优势区域图和电势-pH图以及cT(V)=1.0×10-7 mol·L-1时V-H2O体系的电势-pH图. 电势-pH图结果表明在一定温度和压力下, 各相稳定区取决于体系中溶液态物质的总浓度. 随cT(V)的减小, 溶液稳定区增大, 各固相稳定区均不同程度减小. 相似文献
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本文以NaCl-CaCl2-SrCl2三元计算相图作为“预知图形”,采用高灵敏度的微型差热分析仪,测定该三元相图是三元低共晶体系,其低共晶点E的组成(百分摩尔)为NaCl41.9%,CaCl240.0%,SrCl218.1%,温度为744K。 相似文献
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R. Kh. Shaipov E. Yu. Kerimov E. M. Slyusarenko 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(2):274-277
The hardness values of monophasic (fcc solid solution) and biphasic (fcc solid solution and separated phase) nickel–cobalt alloys doped with tantalum are determined using the Vickers method. Based on the resulting data, a composition–structure–hardness diagram is devised for the Co–Ni–Ta system. 相似文献