2003 Volume 44 Issue 9 Pages 1872-1876
In this paper, effect of the cooling process is examined for the superconductive properties of high Tc Bi-2223/Ag tapes prepared by dip-coating. The short tapes are cooled after the isothermal heat treatment at a controlled temperature profile, which can refine the microstructure. The cooling rate and the slow cooling range are varied, showing that the optimum condition is found where the enhanced Jc is obtained compared to that of normal furnace cooling. Contrarily, Tc did not show an optimum under this condition but increased monotonously with a decrease in the cooling rate and an increase in the slow cooling range. From phase identification, microscopic observation, and quantitative analysis, the microstructure formation in the polycrystalline oxide layer during this process and its relation to these properties are discussed.