[WBP1] Conductor Processing & Evaluation

[WBP1-19] The effect of film thickness on critical current density for TFA-MOD (Y_0.77Gd_0.23)Ba₂Cu₃O_y+BaHfO₃ CCs

*Ryosuke Totsuka¹, Ryusei Kaji¹, Daekyu Lee¹, Yuki Ogimoto¹, Masashi Miura^1,2 (1. Seikei University (Japan), 2. JST-FOREST (Japan))

Keywords:

REBCO,TFA-MOD,critical current density,flux pinning,BHO

The REBa₂Cu₃O_y (REBCO) superconductor with high critical temperature (T_c) and critical current density (J_c) is considered as a promising material for practical applications such as MRIs, generators and motors. Previously, we have succeeded in enhancing the in-field I_c by introducing flux pinning centers while maintaining the material’s crystallinity in Trifluoroacetates Metal Organic Deposition (TFA-MOD) method-grown (Y_0.77Gd_0.23)Ba₂Cu₃O_y+BaZrO₃ ((Y,Gd)BCO+BZO) coated conductors (CCs) through increasing the film thickness (d) [1]. In this work, to investigate the film thickness dependence of J_c, we fabricated 12 vol.% BHO-doped (Y,Gd)BCO CCs with various thicknesses using the TFA-MOD method. (Y,Gd)BCO+BHO films show higher J_c for all thicknesses compared to those in (Y,Gd)BCO and (Y,Gd)BCO+BHO films. For all (Y,Gd)BCO, (Y,Gd)BCO+BZO and (Y,Gd)BCO+BHO films, a rapid decay of J_c with increasing thickness for thinner films was observed, which is caused by the two-dimensional pinning of rigid vortex lines. On the other hand, the J_c value is almost constant for thicker films, which is caused by the three-dimensional pinning. Detailed superconducting properties for (Y,Gd)BCO+BHO CCs with various d will be presented.