CHEMICAL-VAPOR-DEPOSITION OF YBA2CU3O7-X/PRBA2CU3O7-X HETEROSTRUCTURES

A reactor which allows chemical vapor deposition from metalorganic precursors (MOCVD) has been specially designed to synthesize alternate layers of ''superconductor/insulator'' type. The YBa2Cu3O7-1/PrBa2Cu3O7-x studied system is suitable for heteroepitaxial multilayer structures. Thin films, deposited between 750 and 900-degrees-C on MgO {100}, SrTiO3 {100} and LaAlO3 {012} are obtained by thermal decomposition of precursors (tetramethylheptanedionates of Y, Ba, Pr and Cu). YBa2Cu3O7-x layers grown in this reactor have critical current densities of some 10(6) A. cm-2 at 77 K. The temperature dependence of resistivity in the PrBa2Cu3O7-x films shows semiconducting behavior. Growth temperature effect on the interdiffusion at the multilayer interfaces will be studied in the case of two samples elaborated at different temperatures of deposition (750 and 900-degrees-C). Although the element diffusion becomes larger with the temperature of deposition, the superconducting properties are not damaged.