Broadband dielectric spectroscopy of PSN ceramics

The complex dielectric permittivity of ordered and disordered PSN ceramics was measured in the frequency range from 20 Hz to 3 GHz. The anomaly of dielectric permittivity is clearly seen in the region of 115 °C for ordered PSN at all measured frequencies. Disordered PSN exhibits typical relaxor behaviour with a huge frequency dispersion below 125 °C. Calculated distribution of relaxation times shows noticeable influence of polar clusters to the total dielectric spectrum of disordered PSN below 80 °C with the longest relaxation times edge diverging according to the Vogel–Fulcher law. In the case of ordered PSN, two almost not overlapping peaks in the distribution of relaxation times represent displacive lead motions at high frequencies and possible conductivity phenomena at low frequencies and high temperatures.