SECONDARY-ION-MASS-SPECTROSCOPY STUDY OF OXYGEN TRACER DIFFUSION IN A C-AXIS-ORIENTED YBA(2)CU3O(7-DELTA) FILM

The atomic motion of oxygen in a c-axis-oriented YBa2Cu3O7-δ film was studied with implanted O18 as a tracer. Conventional annealing in an oxygen flowing ambient was performed for 1 hour at various temperatures between 175 and 550 °C. Analysis by secondary-ion mass spectroscopy shows that the implanted O18 starts to migrate within the YBa2Cu3O7-δ film at a low temperature, between 250 and 300 °C. Results from gas/solid oxygen isotopic exchange shows that at 315 °C oxygen can enter the YBa2Cu3O7-δ film and confirms the high mobility of oxygen within the film even at this low temperature. The apparent volume diffusivity of the oxygen at 315 °C is found to be ∼1.5×10-13 cm2/s. Short-circuit diffusion is thought to play an important role in determining the high mobility of oxygen in the c-axis-oriented YBa2Cu3O7-δ film. © 1995 The American Physical Society.