Aging in a relaxor ferroelectric: Scaling and memory effects

A crossover as a function of temperature is found in the zero-field aging p roperties of the relaxer ferroelectric Pb(Mg1/3Nb2/3)O-3 Below a temperatur e near which nonlinear susceptibility has indicated a suspected phase trans ition, the time-frequency dependence shows simple scale-independent behavio r resembling that for spin glasses. As in spin glasses, high temperature ag ing is stable as further aging occurs at lower temperature, but not vice ve rsa, indicating hierarchical state arrangement. A more general interpretati on of such effects is briefly discussed.