A new superconducting barium cuprate prepared by molecular beam epitaxy

This paper reviews the MBE-synthesis and structural characterization of a new superconducting barium cuprate Ba2CuO4-delta (Te less than or equal to 90 K). The keys to the successful synthesis of this superconductor are (1) the preparation of Ba2CuO3 in a CO2/H2O-free environment and (2) structural transformation from insulating Ba2CuO3 with 1D CuO chains to superconducting Ba2CuO4-delta with 2D CuO2 planes by strong ozone oxidation after growth. The merits of MBE as a potential synthetic route in the search for new cuprate superconductors are also discussed. (C) 2000 Elsevier Science B.V. All rights reserved.