Largely Anisotropic Superconducting Critical Current in Epitaxially Grown Ba2YCu3O7-y Thin Film

Abstract

Ba₂YCu₃O_7-y (BYCO) thin films have been epitaxially grown on SrTiO₃ substrates by magnetron sputtering. The films exhibit zero resistance at 84 K, with a transition width of 6 K. The resistivity along the basal plane is one order of magnitude smaller than that along the c-axis, and the transport property is more metallic in the former direction. Furthermore, the critical current density is two order of magnitudes larger in the former direction than in the latter direction. These results strongly suggest a quasi-two-dimensional electronic structure in BYCO. The maximum critical current at the liquid nitrogen temperature has reached 1.8×10⁶ A/cm².