Accession Number : ADA311262

Title :   Oxygen Diffusion through Ytterbium-Oxide/Yttrium-Barium-Cuprate Bilayers.

Descriptive Note : Technical rept.,

Corporate Author : ARMY RESEARCH LAB FORT MONMOUTH NJ

Personal Author(s) : Tidrow, Steven C. ; Lareau, Richard T. ; Wilber, William D. ; Tauber, Arthur ; Eckart, Donald W.

PDF Url : ADA311262

Report Date : JUL 1996

Pagination or Media Count : 15

Abstract : We have studied the rate of oxygen diffusion through ytterbium oxide, a buffer and dielectric layer used in high critical temperature superconducting (HTSC) structures. An epitaxial bilayer film of ytterbium oxide on yttrium-barium-cuprate (YBCO) was deposited onto an (001) oriented single crystal MgO substrate using the pulsed laser deposition technique. The rate of oxygen diffusion through the bilayer was investigated from 365 to 655 deg C by post deposition annealing individual sections of the bilayer in 0.5 atm of oxygen-18 enriched molecular oxygen gas. Secondary ion mass spectroscopy was used in depth profile oxygen-18 and oxygen-16 in each sample. Oxygen diffusion coefficients for ytterbium oxide at 365, 465, 555 and 655 deg C were determined to be roughly (6,16, 360 and 200) x 10(exp -14)/sq cm/s, respectively. For temperatures greater than about 500 deg C, these diffusion rates can limit oxygen intake into underlying YBCO films; therefore, HTSC multilayer devices that utilize ytterbium oxide as a dielectric layer may require longer annealing cycles in order to fully oxygenate each underlying HTSC layer.

Descriptors :   *LAYERS, *MASS SPECTROSCOPY, *OXYGEN, *OXIDES, *DIFFUSION, *YTTRIUM, *YTTERBIUM, IONS, ANNEALING, HIGH TEMPERATURE, DIELECTRICS, FILMS, SINGLE CRYSTALS, EPITAXIAL GROWTH, SUBSTRATES, PULSED LASERS, CYCLES, CRITICAL TEMPERATURE, DEPOSITION, COPPER, DIFFUSION COEFFICIENT, BARIUM, MOLECULAR PROPERTIES, MAGNESIUM OXIDES.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Lasers and Masers
      Crystallography
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE