Melt textured superconducting YBCO films with anapproximate thickness of 50-120 µm and Tc(0) values ranging between 86.5and 88.5 K have been prepared on polycrystalline yttria-stabilized zirconiasubstrate, toughened by 20 wt.% Al2O3. Between thesubstrate and superconducting film an interface layer was formed. Their AC andDC magnetization characteristics were measured and the values of the magneticpenetration field Hp1 were estimated. The penetration field Hp1 of 2.7 kA m-1was obtained for the thinner film deposited with a higher spin coating rate,while for the thicker film deposited with a lower spin coating rate Hp1 = 4.4 kAm-1. Repeated temperature cycling between room and liquid nitrogentemperatures and corresponding measurement of the magnetization hysteresiscurves reveal the significant decrease of the grain superconducting pro-pertiescaused probably by arising cracks.
