Preparation and properties of melt-processed thick films of YBCO

A detailed study has been carried out of the successful fabrication of high current capacity, thick films of YBCO on yttria-stabilized zirconia substrates. This has involved the optimization of a number of processing parameters including material composition, processing temperatures and times, ink additives and so on. As a result of this work, thick films have been obtained with thicknesses of as little as 7μ, which are superconducting withT _c=91·5 K and have critical current densities at 77 K of almost 3×10³ Acm⁻². This current decreases rapidly with increasing magnetic field strength, reaching an almost constant value of 100–200 Acm⁻² at 0·4 T.