Optimization of YBa/sub 2/Cu/sub 3/O/sub 7-x/ thick films on yttria stabilized zirconia substrates

This report describes the optimization of the firing process used in the production of YBa/sub 2/Cu/sub 3/O/sub 7-x/ thick films screen printed on yttria-stabilized zirconia substrates. The highest critical current density (J/sub c/) values were obtained by employing a double layer printing technique in which a single superconductive layer was printed onto a zirconia substrate and fired, followed by the subsequent deposition and firing of second superconductive layer. Using this procedure, thick film superconductors with a superconductive transition temperature (T/sub c/) of 85 K and a J/sub c/ of 130 A/cm/sup 2/ were obtained by sintering the printed films at 950/spl deg/C for 90 minutes, followed by a six hour oxygen annealing treatment at 600/spl deg/C. Specimens sintered for comparable periods of time at 940 and 960/spl deg/C did not exhibit superconductive behavior above 77 K due to either incomplete microstructural development or thermal decomposition of the superconductive phase respectively.<>