YBA2CU3O7 GROWTH ON METAL SUBSTRATES WITH SRTIO3 BUFFER LAYER BY METAL-ORGANIC CHEMICAL-VAPOR-DEPOSITION

We prepared oxide superconducting YBa2Cu3O7-x thin films on Hastelloy substrates with a SrTiO3 buffer layer by metal-organic chemical vapor deposition (MOCVD) using a single source of tetrahydrofuran solution. To clarify the cause of poor superconducting properties, the cross sec tion of YBa2Cu3O7-x/SrTiO3/Hastelloy was examined by TEM. The YBa2Cu3O 7-x and SrTiO3 layers grew perpendicular to the Hastelloy surface, whi ch was columnar. The orientation of the YBa2Cu3O7-x layer seems to dep end on that of the SrTiO3 layer. As a result, it is considered that th e deposition of a good single-crystalline buffer layer on Hastelloy is the most important factor for obtaining excellent YBa2Cu3O7-x films.