Oxygen-ion diffusion in YBa2Cu3O7-delta ceramics

Oxygen diffusion coefficients for YBa2Cu3O7-delta (YBCO) ceramics were dete rmined from an isotope-gas exchange measurement using the stable isotope O- 18 as a tracer between 450 degrees C and 700 degrees C. During the experime nts, the oxygen deficient value (delta) is kept constant by controlling the oxygen pressure of the reactor. The oxygen diffusion in YBCO ceramics is r epresented by a single equation D = 7.8 X 10(-1) exp(-1.05 eV/RT) cm(2)/s f or the various oxygen deficient specimens we examined. The present results suggest that the oxygen diffusion rate in YBCO does not depend on the oxyge n deficiency. (C) 2000 Elsevier Science B.V. All rights reserved.