Abstract
The EPR spectra of Pb5Ge3O11 : Gd3+ have been studied in the temperature range 300–520 K. Anomalous EPR line width broadening and line splitting has been observed on going through the ferroelectric phase transition. The temperature dependencies of the EPR line width and the line splitting are used to estimate the extension of the critical interval where thermodynamic anomalies are expected to be driven by fluctuations. The temperature behaviour of the local order parameter and its fluctuations is analyzed.