High critical current density thick MOD-derived YBCO films

High critical current density thick MOD (metalorganic-deposition)-derived B a2YCu3O7-x (BYC) films have been prepared on latticed matched single crysta l lanthanum aluminate substrates. Critical current densities of approximate ly one million amps per square centimeter (at 77 K) have been obtained from one micron thick BYC films. These superconducting films were prepared from a single MOD coating. Substrate coatings of a mixed metal trifluoroacetate precursor were first converted into high quality mired metal oxyfluoride f ilms by heat treating under controlled conditions. These films were then pa tterned and subsequently converted into epitaxial BYC by exposure to water vapor at higher temperatures. High critical current density films were obta ined by controlling the conversion kinetics of the mixed metal oxyfluoride films into BYC.