We have investigated the room-temperature oxygen depletion in the near-surface region of YBa2Cu3Ox samples kept under high vacuum. Results obtained from secondary-ion-mass-spectroscopy and four-probe-conductivity measurements are presented. The depletion process is limited by oxygen out diffusion in the samples with diffusion coefficients of 10-18-10-19 cm2/s. The reverse oxygen in-diffusion process occurs in oxygen atmosphere. The oxygen out-diffusion process can be accelerated by direct ultraviolet light (UV) irradiation of the samples in vacuum. The in-diffusion process is accelerated if UV light is used in oxygen atmosphere to produce ozone and atomic oxygen.
ASJC Scopus subject areas
- Condensed Matter Physics