Calorimetric baseline fitting: Application to titanite

In order to analyse calorimetric measurements of a phase transition, it is necessary to determine the baseline from which the excess specific heat is measured. In this study, this baseline is determined by using the constrain t that the resulting heat capacity anomaly must be consistent with measurem ents of the phase transition by other techniques. The method is particularly useful when other mechanisms make it difficult t o predict the low-temperature behaviour of the baseline. Titanite provides an example of this, since the antiferroelectric transition temperature is c lose to the temperature at which the phonon contribution to the specific he at begins to fall rapidly.