Superconducting properties of Ba2YCu3O7−x thin films prepared by chemical vapor deposition on SrTiO3 and a metal substrate

Superconducting Ba2 YCu3 O7−x thin films were prepared by chemical vapor deposition using β-diketonate chelates on SrTiO3 single crystalline substrates, metal substrates, and metal substrates with a polycrystalline SrTiO3 buffer. The temperatures of complete superconducting transitions were observed at 89, 81, and 84 K, respectively. Reduced critical current density of the film on a single crystalline substrate in magnetic fields up to 600 mT at 77 K remained one or two orders of magnitude higher than that of powder metallurgical processed specimens. According to x-ray diffraction patterns, the existence of a well-oriented orthorhombic Ba2 YCu3 O7−x structure has been confirmed in all specimens.