Thermochimica Acta, Vol.430, No.1-2, 135-141, 2005
Intrinsic compensation phenomenon in thermally stimulated depolarisation studies
The compensation behaviour as observed in thermally stimulated depolarisation currents (TSDC) corresponds to the linear relationship found between the Arrhenius (or Eyring) apparent thermokinetic parameters obtained in a series of thermal sampling (TS) experiments performed in the region of cooperative relaxation processes, particularly around the glass transition of glass forming materials. The compensation effect exhibits the same features of the intrinsic compensation found for any given TS curve, where the values of E-a and tau(0), in the region where the sum of square residues is low, are highly correlated, being this correlation similar to the conventional compensation. This intrinsic compensation is a result, and exhibits the same features, of the compensation found in the description of a given set of points obtained with the Arrhenius equation with the own Arrhenius equation. This compensation is transmitted directly to the equation that describes the temperature dependence of the depolarisation currents, J(T), as a nearly direct relationship exists between J(T) and tau(T). In fact, it was shown that J(7) for an elementary process could be approximated by P-0 exp[-c/tau(T)]/-tau(T), c being a constant. (c) 2005 Elsevier B.V. All rights reserved.