The polarisation decay function and freezing scenario in dipole glasses

Abstract

Discharge currents and susceptibility functions are given for KTaO 3 doped with Li. These functions are parametrised in terms of a Kohlrausch-Williams-Watts decay function involving a stretched exponential in the time domain. The parameters, namely the size of the relaxation step, the relaxation rate and the stretch index are given as a function of temperature. The step size shows the usual cusp at Tf whereas neither the relaxation time nor the stretch index are critical functions of T-Tf, where Tf denotes the transition temperature to the dipolar phase. Below Tf, arithmetic decay is observed.