HIGH CRITICAL CURRENT DENSITIES IN YBA2CU3O7-X THIN-FILMS FORMED BY METALORGANIC CHEMICAL VAPOR-DEPOSITION AT 730-DEGREES-C

YBa2Cu3O7-x superconducting thin films with a critical current density of 2.3 x 10(6) A/cm2 at 77.7 K and 0 T were prepared by a metalorganic chemical vapor deposition process. The films were formed in situ on LaAlO3 at a substrate temperature of 730-degrees-C in 2 Torr partial pressure of N2O. Resistivity and magnetic susceptibility measurements of the as-deposited films show a sharp superconducting transition temperature of 89 K with a narrow width of less than 1 K. Critical current densities were measured by the dc transport method with a patterned bridge of 120-mu-m x 40-mu-m. Both x-ray diffraction and high-resolution electron microscopy measurements indicate that films grew epitaxially with the c axis perpendicular to the surface of the substrate.