(Tl0.5Pb0.5)(Sr0.8Ba0.2)2Ca2Cu3Oy superconducting thick films with high critical current densities in magnetic fields

Superconducting (Tl0.5Pb0.5)(Sr0.8Ba0.2)2Ca2Cu3Oy films with thicknesses from 1 µm to 2 µm were prepared by screen printing of the precursor material on lanthanum aluminate substrates followed by ex situ thallination. Texture analysis confirmed that highly c-axis oriented samples with critical temperatures Tc(0) between 117 and 119 K and with transition widths ÄT(90-10%) of 1 K have been fabricated. The current densities in self-field were above 1.2 x 1010 A m-2 at 77 K. These materials show also excellent current densities in external magnetic fields without the introduction of artificial pinning centers. For H || c jc-values of 4 x 109 A m-2 at 77 K for external fields of 6 T were observed. For H || ab current densities of 1 x 109 A m-2 were still measured at 1 T.