Elastic after-effect due to oxygen relaxation in YBa2Cu3O(7-(delta)) above (Tc).

摘要

Isothermal elastic after-effect measurements to obtain relaxation times for the stress-induced motion of oxygen in YBa(sub 2)Cu(sub 3)O(sub 7 (minus)(delta)) have been made from 50(degree)C to 110(degree)C. These results extend our previous internal friction measurements of the same oxygen relaxation to lower temperatures. The combined results, which cover nine orders of magnitude in relaxation time, show a classical Arrhenius temperature dependence, activation, energy Q=1.3 (plus minus) 0.01 eV and attempt frequency (tau)(sub 0)=1.6 (times) 10(sup (minus)13)s (log (tau)(sub 0)=(minus) 12.79 (plus minus) 0.13). The mechanism of the relaxation is considered to be stress-induced ordering of oxygen atoms on the CuO basal plane. Diffusivities obtained from these results are compared with those from tracer diffusion of oxygen. 12 refs., 3 figs.