Isothermal and non-isothermal kinetic study of the PbGeO3 solid-solid phase transition

A kinetics study on PbGeO3 solid-solid phase transition was realised by means of differential scanning calorimetry and time-resolved X-ray powder diffraction. Isothermal and non-isothermal Johnson-Mehl-Avrami equations were applied to obtain both the activation energy Ea and the Avrami coefficient n. The latter parameter has been related to morphological evidences collected by scanning electron microscopy. The limits of the applied theory, i.e., the Arrhenian behaviour of the growth rate and a steady-state nucleation rate, are finally discussed in terms of recent theoretical developments.