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

（RE）-Ba-Cu-O块状高温超导体（HTS）具有产生大磁场的潜力，可用于稳定磁场轴承、飞轮储能系统和永磁器件。为此，有必要制造大型的无晶界块体（RE）BCO材料。在此，我建议制造具有高困场的大型单粒超导体，并评估其工程应用的特性。详细研究了各种（RE）BCO伪单晶的观察过程、基本生长条件和优化各种（RE）BCO体系的基本工艺参数。此外，还将研究通过改造微观结构、改变载流子浓度以及在块状超导基体中引入自然和人工钉钉中心来增强（RE）BCO单晶粒的电流密度和不可逆场。本研究工作的结果将用于制造具有超大捕获场的大型单粒超导体。对于复杂形状的超导体、特定的医学和工程应用来说，连接单个晶粒是必要的，为此，本工作建议为高温超导开发有效的连接工艺。目前用于高温超导微波应用的材料制造技术主要基于薄膜。这些薄膜器件仅限于相对简单的微波滤波器几何形状，并且需要复杂的设备来沉积。我们在此建议用块状超导体制造更复杂几何形状的微波谐振器和低表面电阻的滤波器。据设想，这将使制造低成本、大规模生产的3d设备成为可能。

(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.