We focused on an improvement of
Jc in low magnetic fields (including self-field) for applications to operations in low magnetic fields such as power cables and fault current limiters. We assumed that motion of the fluxes leads to a degradation of
Jc even in low magnetic fields. In order to improve the
Jc in low magnetic fields, we introduced a small amount of BHO as artificial pinning centers to YBCO thin films and evaluated the superconducting properties. We fabricated BHO-doped YBCO thin films on IBAD-MgO substrates using the pulsed laser deposition method and an excimer laser. The additive amount of BHO was in the range of 0.21 – 3.37 vol.%. The
Tc of all the samples was approximately 88 K and this
Tc was reduced approximately 1 K compared with the value for a pure-YBCO thin film. On the other hand,
Jc at 77 K in the self-field (
Jcself) of 0.42 vol.% BHOdoped samples was 5.76 MA/cm
2. These values were higher than the
Jcself (3.68 MA/cm
2) of the pure-YBCO thin film. In addition, increasing
Jcself improved the
Jc in low magnetic fields below 1 T.
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