纳米铁电相增强YBCO薄膜磁通钉扎性能的研究

项目名称： 纳米铁电相增强YBCO薄膜磁通钉扎性能的研究

项目编号： No.51202190

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机非金属材料学科

项目作者： 雷黎

作者单位： 西安理工大学

项目金额： 25万元

中文摘要： YBCO涂层导体凭借其优异的超导性能将成为替代铋系带材的第二代高温超导带材。然而，YBCO薄膜的临界电流密度随外磁场的增大而迅速减小的问题却成为涂层导体在强电领域应用的主要障碍。我们的前期研究发现，通过化学掺杂的方法引入Y2O3纳米颗粒可显著增强YBCO薄膜的磁通钉扎性能，有效提高磁场下薄膜的临界电流密度。在此基础上，若能在薄膜中引入具有特殊物理性质的纳米相，那么在增强YBCO薄膜本身超导性能的同时也可能赋予其一些新的物理特性。该项目拟通过化学溶液掺杂的方法制备超导/单一铁电相和超导/(铁电-铁磁混合相)纳米复合薄膜，研究铁电、铁磁等功能性纳米相对超导薄膜磁通钉扎性能的影响机制，以期获得额外的磁通钉扎贡献，进一步增强YBCO薄膜的磁通钉扎性能，使涂层导体在尽可能宽的磁场角度、大小及温度范围内获得更高的载流能力。该研究无论对高性能涂层导体的开发应用还是对高温超导机制的深入理解均具有重要意义。

中文关键词： 高温超导；异质外延；晶体缺陷；磁通钉扎；感光溶胶-凝胶

英文摘要： YBCO Coated Conductors will become the second high-temperature superconductor tapes instead of the Bi2223 tapes due to their excellent superconducting properties. However, the critical current density decreases rapidly as the applied magnetic field increases, which has been the main obstacle for coated conductors to be applied in the heavy current field. Our previous results showed that the flux pinning of YBCO films can be markedly enhanced through introducing Y2O3 nanoparticles into YBCO matrix, thus resulting in the improved critical current density of YBCO films at applied magnetic field. Based on this result, if one can introduce some nanophases with special physical properties into YBCO matrix to form YBCO functional nanocomposite film, the superconducting properties of YBCO films could be improved and endowed with some novel physical properties. In this project, the functional nanocomposite films such as superconductor/single ferroelectric phase and superconductor/(ferroelectric-ferromagnetic mixture phases) will be prepared by using chemical solution doping method, and the influence mechanism of these functional nanophases on the flux pinning of YBCO films is discussed. It could be expected that the flux pinning of YBCO films is further enhanced by an additional pinning contribution, thus bringing high c

英文关键词： High-temperature superconductivity；Heteroepitaxy；Crystal defect；Flux pinning；Photosensitive sol-gel