2022 年 57 巻 6 号 p. 375-381
In superconducting coil applications, magnetic fields are applied to superconducting material from various directions. YBa2Cu3Oy (YBCO) coated conductor containing BaHO3 (BHO) flux pinning centers is expected to be used as coil application. In this study, BHO-doped YBCO films were prepared by changing the substrate temperature (Ts) and thickness per pulse (tpulse) using the pulsed laser deposition method. As a result, the isotropy of the critical current density vs field angle (Jc-θ) curve was improved in the BHO-doped YBCO film fabricated under the condition of low Ts and high tpulse. In the cross-sectional transmission electron microscopic observation, it was confirmed that BHO nanorods with gradually increasing tilt angles grew in BHO-doped YBCO film. The surface atomic force microscope images also confirmed that YBCO grains grew in three-dimensional island growth. The shape of BHO is determined by the growth rate of YBCO and BHO, which affects the tilt angle of the BHO nanorods.
