[WBP1] Conductor Processing & Evaluation

[WBP1-18] The influence of different hole concentrations on the superconducting properties of TFA-MOD (Y_0.77Gd_0.23)Ba₂Cu₃O_y films

*Ryuga Matsuhira¹, Takumi Hirose¹, Ryona Fujimoto¹, Yuki Ogimoto¹, Masashi Miura^1,2 (1. Seikei Univ. (Japan), 2. JST-FOREST (Japan))

Keywords:

REBCO,TFA-MOD,critical current density,Jc

The REBa₂Cu₃O_y (REBCO) superconductors with high critical temperature (T_c) and critical current density (J_c) are considered as a candidate material for superconducting applications. From previous research, it is known that the superconducting properties of REBCO superconductors change depending on the hole concentration (p). Recently, we have reported that a higher J_c property is obtained for over-doped (p = 0.177) (Y_0.77Gd_0.23)Ba₂Cu₃O_y ((Y,Gd)BCO) films fabricated by the Trifluoroacetates Metal Organic Deposition (TFA-MOD) method [1]. Although the properties between the optimally-doped and the over-doped region have been actively investigated because the J_c property is a crucial parameter for practical applications, it is also important to elucidate the properties over a wide range of p including the under-doped region for better understanding.In this work, to study the effect of p on the superconducting properties, we fabricated (Y,Gd)BCO films on the SrTiO₃ substrates with various p using the TFA-MOD method. The under-doped films showed almost the same T_c as the over-doped films, but the J_c was much lower than that of othe ver-doped films. In addition, an increase in the c-axis length with decreasing p was observed, implying that the mass anisotropy might also be changing depending with the p. Detailed superconducting properties for (Y,Gd)BCO films with various p will be presented.