Microstructural observation of YBCO superconducting tape with textured Cu substrate

The microstructure of YBa2Cu3O7-δ (YBCO) superconducting wire with textured Cu substrate was investigated using an electron back scattering pattern (EBSP) and transmission electron microscopy (TEM). The structure of this wire is YBCO/CeO2/YSZ/CeO2/electro-plated Ni/textured Cu/SS. The YBCO film with Jc of 3.2 MA/cm2 was prepared for this observation. The crystallographic orientation relationship between the Ni layer and the Cu layer was investigated. The good cube-on-cube epitaxy including the position and the direction of the grain boundaries were confirmed. In addition, the clear layered structure and fact that there were no out-of-phase components were confirmed. From the electron beam diffraction, the crystallographic orientation relationship was confirmed as YBCO(006)//CeO2(002)//YSZ(002)//CeO2(002)//Ni(002) and YBCO(200)//CeO2(220)//YSZ(220)//CeO2(220)//Ni(200). From the results of energy dispersive X-ray spectrometry (EDS), the diffusion of Ni and Cu were confirmed. The need to optimize the Ni-layer thickness was suggested. (author)