A new superconducting barium cuprate prepared by molecular beam epitaxy

Abstract

This paper reviews the MBE-synthesis and structural characterization of a new superconducting barium cuprate Ba 2CuO 4− δ ( T c≤90 K). The keys to the successful synthesis of this superconductor are (1) the preparation of Ba 2CuO 3 in a CO 2/H 2O-free environment and (2) structural transformation from insulating Ba 2CuO 3 with 1D CuO chains to superconducting Ba 2CuO 4− δ with 2D CuO 2 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.