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基于碘量法测定高温超导氧化物氧含量的方法,总结出固溶化合物Sm_(1+x)Ba_(2-x)Cu_3O_n的氧含量n随固溶度x变化的规律性;从理论分析和实验测定得出在固溶区域内,Sm_(1+x)Ba_(2-x)Cu_3O_n的氧含量n与替代程度x呈线性关系,超出固溶极限x_0,直线斜率将发生明显变化,此结果与X射线粉末衍射结果基本一致。关键词:碘量法,氧化物高温超导体,氧含量,固溶体。 稀土氧化物高温超导体123相合成过程中常伴有少量杂相产生,少量杂质对超导体的超导电性影响很大,在含La、Nd、Sm、Eu等体系中,123相常形成如R_(1+x)Ba_(2-x)Cu_3O_n替代或固溶体,准确测定固溶体极限x_0,对此类超导单晶的制备工艺和理论研究十分重要。 中子衍射表明,在R_(1+x) 、Ba_(2-x)Cu_3O_n固溶体中,稀土离子R代替Ba离子,其作用结果之一是固溶体化合物氧含量的变化呈一定的规律性。 本文采用无机分析化学中的碘量法,测定固溶体化合物Sm_(1+x)Ba_(2-x)Cu_3O_n的氧含量,从理论和实验分析高温超导体氧含量n随固溶度x变化的规律,从而确定固溶体极限X_0。
Based on the method of iodometric method for the determination of the oxygen content of high-temperature superconducting oxides, the regularity that the oxygen content n of the solid-solution compound Sm_ (1 + x) Ba_ (2-x) Cu_3O_n changes with the solid- The experimental results show that the oxygen content n of Sm 1+ x Ba 2-x Cu 3O_n in the solid solution region is linear with the degree of substitution x. When the solid solution limit x 0 is exceeded, the slope of the straight line will change obviously. Results and X-ray powder diffraction results are basically the same. Key words: Iodometric method, high temperature oxide superconductor, oxygen content, solid solution The rare earth oxide high temperature superconductor 123 phase synthesis process often accompanied by a small amount of heterogenous phase, a small amount of impurities on the superconductor superconductivity greatly affected, including La, Nd, Sm, Eu and other systems, 123 often form such as R_ (1 + x) Ba_ (2-x) Cu_3O_n substitution or solid solution, and the limit of solid solution x_0 can be accurately determined. It is very important for the preparation technology and theoretical research of such superconducting single crystals. The neutron diffraction shows that the rare earth ion R replaces the Ba ion in the R_ (1 + x), Ba_ (2-x) Cu_3O_n solid solution. One of the effects of this is that the change of the oxygen content of the solid solution compound has a certain regularity. In this paper, the iodine content in inorganic analytical chemistry was used to determine the oxygen content of the solid-solution compound Sm_ (1 + x) Ba_ (2-x) Cu_3O_n. Theoretical and experimental analysis of the variation of oxygen content n with solid solution x in high temperature superconductor, Thereby determining the solid solution limit X_0.