Development of Long YBCO Coated Conductor by IBAD-PLD Method

∼Self-Epitaxial PLD-CeO₂ Cap Layer on IBAD Buffer Substrate∼

Abstract

Processing of a CeO₂ layer on an IBAD-Gd₂Zr₂O₇ buffer tape was investigated as a cap layer. In the process of this study, we found that the CeO₂ cap layer by the PLD method on the IBAD buffer tape brought about high in-plane grain alignment without Ar ion assistance such as the IBAD process. The Δφ value, degree of the in-plane grain alignment decreased from 25.4 degrees and 11.6 degrees for the IBAD-GZO to 4.9 degrees and 2.4 degrees for the PLD-CeO₂, respectively. We call this phenomenon “self-epitaxial PLD-CeO₂ cap layer”. Then, we suggested a new process which is a combination of a thin IBAD-GZO by short time deposition and a PLD-CeO₂ with high rate deposition in order to enhance the fabrication rate for the buffer layer process. The new self-epitaxial process is very promising as a buffer layer process in terms of both high grain alignment and rapid fabrication.