Quick Exploration of Artificial Pinning Centers Suitable for REBa₂Cu₃O_y Thin Films by Means of Combinatorial-PLD Method

Abstract

The Combinatorial-PLD (C-PLD) method is an efficient way to screen the optimal composition in YBCO thin films because it is possible to create a film with a continuously changing composition across a single substrate. In this paper, we report on the quick exploration of optimal content for flux pinning materials in YBCO thin films using the C-PLD method. We optimized the content of BaSnO₃ and the optimal content was almost the same as that of another report. Candidates for new pinning materials were also explored using the C-PLD method. Furthermore, we substituted a part of the Cu in YBCO films with various types of 3d-metals. As a result, upper critical fields (H_c2) were improved by substituting Co and Ni. Though H_c2 in a pure-YBCO film was about 100 T at 0 K, the YBCO films with the substitution of Co and Ni achieved an H_c2 of about 270 T at 0 K.