S. Sadewasser et al., Pressure dependence of T-c to 17 GPa with and without relaxation effects in superconducting YBa2Cu3Ox, PHYS REV B, 61(1), 2000, pp. 741-749
Hydrostatic high-pressure studies to 17 GPa were carried out on superconduc
ting YBa2Cu3Ox over the full range of oxygen content x. The observed bell-s
haped T-c(P) dependences are found to depend markedly on the temperature at
which the pressure is changed. The time-dependent relaxation processes are
studied using both T-c and the electrical resistivity at 298 K as probes.
The activation volume for oxygen diffusion is determined from the pressure-
dependent activation energy and compared with estimates from a simple hard-
sphere model.