Large, single grain (RE)BCO superconductors for high magnetic field and microwave device applications

(Re)-BaCuO块体高温超导体(HTS)具有产生大磁场的潜力，可用于稳定磁场的轴承、飞轮储能系统和永磁体设备。为此，有必要制备大尺寸、无晶界的BCO材料。在这里，我建议制作具有高陷陷场的大尺寸单晶超导体，并专门针对工程应用来评估其性能。将详细研究各种(RE)BCO伪单晶的生长过程、基本生长条件以及各种(RE)BCO系统的基本工艺参数的优化。此外，还将通过改变(RE)BCO单晶的微观结构、改变载流子浓度以及在块体超导基质中引入自然和人工钉扎中心来提高(RE)BCO单晶的电流密度和不可逆场。这项研究工作的结果将被用于制备具有非常大的陷阱场的大尺寸单晶超导体。对于特定的医疗和工程应用，对于复杂形状的超导体来说，单个单晶的连接是必要的，本工作建议为此目的开发有效的高温超导连接工艺。目前用于高温超导微波应用的材料制备技术主要基于薄膜。这些薄膜器件仅限于相对简单的微波滤光片几何结构，并且需要复杂的设备进行沉积。我们建议用块状超导体制作具有更复杂几何结构、低表面电阻的微波谐振器和滤波器。据设想，这将使低成本、大规模生产的3-D设备得以制造。

(RE)-Ba-Cu-O bulk high temperature superconductors (HTS) have the potential to generate large magnetic fields for use in stable magnetic field'bearings, flywheel energy storage systems and permanent magnet devices. For this purpose it is necessary to fabricate large, grain-boundary free bulk (RE)BCO materials. I propose here to fabricate large single grain superconductors with high trapped fields and evaluate their properties specifically for engineering applications. A detailed study of the seeing process, basic growth conditions for various (RE)BCO pseudo-single crystals and optimisation c fundamental processing parameters for various (RE)BCO systems will be carried out. In addition, study on theenhancement of the current density and the irreversibility filed of (RE)BCO single grains by engineering the microstructure, altering the carrier concentration and introduction of natural and artificial pinning centers to the bulk superconducting matrix will be carried out. The results obtained in this research work will be used to fabricate large single grain superconductors with very large trapped fields. Joining of the individual single grains is necessary for complex shaped superconductors, for specific medical and engineering applications and it is proposed in this work to develop effective joining process for HTS for this purpose. Current technologies for the fabrication of materials for HTS microwave applications have been based primarily on thin films. These thin film devices are limited to relatively simple microwav filter geometries and require sophisticated equipment for their deposition. We propose here to fabricate microwave resonators and filters of more complex geometries with low surface resistance from bulk superconductors. It is envisaged that this will enable fabrication of low cost, mass produced 3-D devices.