“…From this figure, the activation energy and the s 0 of the peak deduced from the slope and the intercept of the line are 0.34 eV and 6.5 Â 10 À11 s, respectively. The activation energy is close to those values for relaxation associated with interstitial oxygen in RuSr 2 GdCu 2 O 8 (0.36 eV) and YBaCuFeO 5+d (0.28 eV) [29,30].…”