Properties of Bi-2223 thick films on a MgO substrate prepared by a coating method

Fault current limiters for electric power systems have been researched. We have been studying on a inductive type superconducting fault current limiter. The limiter has superconducting cylinder as active element. It is necessary for practical use of the superconducting fault current limiter that superconductor has high critical current density (Jc). So as to get high Jc, we tried Bi-2223 as a material for the superconductor, and prepared Bi-2223 thick film. Raw paste of Bi system was coated on a polycrystalline MgO substrate and then was sintered in the air with intermediate pressing by a cold-isostatic-pressing (CIP) technique. The sintered Bi-2223 thick film had good crystal orientation. The Jc of the 500 μm thick film was over 6000 A/cm² at 77 K.