[19p-C213-1~18] 11.1 Fundamental properties

△ [19p-C213-2] Acceleration mechanism of oxygen diffusion in REBCO melt-solidified bulks
by annealing under humid oxygen atmosphere

〇Takanori Motoki¹, Yu Yanai¹, Kota Nunokawa¹, Shinkichi Gondo¹, Shin-ichi Nakamura², Jun-ichi Shimoyama¹ (1.Aoyama-Gakuin Univ., 2.TEP)

Keywords:REBCO melt-solidified bulk, oxygen diffusion

In order to properly control the carrier doping state of REBCO melt-solidified bulks, long-time oxygen-annealing for hundreds of hours is necessary. We have found that annealing under humid oxygen atmosphere accelerates oxygen diffusion in REBCO bulks by a factor of two than that under dry oxygen annealing. In this study, in order to elucidate this acceleration mechanism, systematical evaluation on microstructures and superconducting properties has been conducted.