Fabrication and superconducting properties of Bi2Sr2CaCu2Oy multilayer tape prepared by continuous heat treatment

Flesible Bi-2212 multilayer tapes of similar to 80 m length were prepared by a combination of the oxide-painting method and the continuous heat-treatment technique. The tapes were heat-treated by passing them through a tube furnace having temperature gradient which induced partial melting and slow cooling. The tapes had critical current density (J(c)) values higher than 1 x 10(5) A/cm(2) at 4.2 K and 12 T. The tapes showed excellent J(c) vs strain properties. J(c) was almost constant up to the bending strain of 0.7% (the bending diameter of 30 mm). Hence the ''react & wind'' technique could be applied to the fabrication of coils. A small pancake coil fabricated by the ''react & wind'' technique had J(c) values almost equal to those of short straight tapes.