Growth and characterization of Bi2Sr2CaCu2Oy thick films on bare polycrystalline Y-stabilized ZrO2 substrates

We have successfully grown Bi2Sr2CaCu2Oy thick films, with a Tc0 of 88 K, on polycrystalline Y-stabilized ZrO2 substrates using a partial melting technique. We have found that the partial melting temperature Tm and the cooling rate strictly control the phase purity and the orientation of the resultant thick films. For optimum processing, x-ray diffraction analysis and scanning electron microscopy results reveal that the thick films are single 2212 phase and well c-axis oriented. We obtained a value of Tc0 as high as 88 K and determined the critical current density Jc in the zero magnetic field to be more than 103 A cm-2 at 60 K and more than 4x103 A cm-2 at 30 K. The Jc dependence on temperature shows that, near Tc, Jc is proportional to (1-T/Tc)n, with n∼2 for the single 2212 phase and n∼1.5 for the 2201 phase mixed films, which correspond to the results of the superconducting-normal-superconducting or superconducting-normal-insulating-superconducting models, respectively. (author)