The antiferrodistortive soft mode was detected at the M point of the Brillouin zone in a crystal PbZr0.024Ti0.976O3 using the method of inelastic scattering of synchrotron radiation. The performed group-theoretical analysis and calculations of inelastic structural factors made it possible to relate the detected critical excitation to oxygen octahedra rotations. The traced temperature evolution of the soft mode frequency obeys the Curie-Weiss law with Curie temperature T AFD = 438 ± 5 K, which is close to the ferroelectric Curie temperature T FE = 479.5 K.

The technique of studying the synchrotron radiation scattering on single crystals over wide temperature range using an original miniature device for applying an electric field to a sample is described. A specific feature of the device is the possibility of its application with various heating and cooling systems. The technique was used at BM01 beamline at the European Synchrotron Radiation Facility (ESRF) for the study of the influence of electric field on the processes of structural transformation in lead zirconate–titanate single crystal with a low titanium concentration. The efficiency of the technique proposed in this work is demonstrated and the results of the preliminary analysis of the results are presented.