铋的不同价态对铋酸钡基超导化合物性能的影响

项目名称： 铋的不同价态对铋酸钡基超导化合物性能的影响

项目编号： No.21271014

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 李国宝

作者单位： 北京大学

项目金额： 80万元

中文摘要： 超导体在科研、医学、能源等诸多领域存在着广泛的应用，相关的研究非常活跃。掺钾的铋酸钡基超导体是三维的钙钛矿结构,与多数高温超导体(Tc>30K)如铜基、铁基及二硼化镁类超导体为层状化合物存在显著的不同；这使得研究这类化合物的超导机制非常重要。目前发现该类化合物的超导电性与化合物中的Bi(V)和Bi(III)离子的比例有着很大的关联。本项目将致力于先合成不同掺杂程度的目标化合物Ba1-xAxBi1-yMyO3-zXz(A=Li+, K+,…; M=Ta5+,Fe3+,…; X=N3-, F-,…)，调控Bi(V)和Bi(III)的比例；再测量其超导电性，并用X-ray、中子粉末衍射及电子衍射来研究其结构变化；从而可以得到更多的实例化合物来研究在各种不同条件下(例如掺杂离子种类的不同)该类化合物的超导电性与化合物中Bi(V)和Bi(III)离子比例的关系。这将有助于我们对超导本质的理解。

中文关键词： BaBiO3；超导体；拓扑反应；钙钛矿；掺杂

英文摘要： Superconductivity has been studied extensively because superconductors have many applications or potential applications in scientical area, medicine, energy and so on.Having the perovsikte structure, which is different from other high-temperature superconductors (Tc>30K) such as copper-oxide superconductors, iron-based superconductors, MgB2-related superconductors with layered structures, Ba1-xKxBiO3-related superconductors are very useful to study the mechanism of superconductivity. It has been shown that the superconductivity of Ba1-xKxBiO3-related superconductors are related to the ratio of Bi(V) and Bi(III) in the compounds. Therefore, our preject focuses on such a question: firstly try our best to synthesize the compounds Ba1-xAxBi1-yMyO3-zXz(A=Li+, K+, …; M=Ta5+, Fe3+, …; X=N3-, F-, …)； then to characterize their superconductivity, and to analyze their structure with the help of powder X-ray, neutron and electron diffraction；after that we expect that more Ba1-xKxBiO3-related superconductors are obtained and we can study the relationship between the superconductivity and the ratio of Bi(V):Bi(III) in these compounds, which may improve our understanding to the origin of superconductivity.

英文关键词： BaBiO3；superconductor；Topotactic reaction；perovskite；doping