Distribution of the relaxation times of the new relaxor 0.4PSN–0.3PMN–0.3PZN ceramics

The real distribution function of the relaxation times g(τ) of the relaxor ferroelectric ceramics 0.4PSN–0.3PMN–0.3PZN is calculated from the experimental dielectric spectra obtained in the frequency range from 20 Hz to 1.25 GHz. Below the Burns temperature TB ≅ 380 K, where the clusters begin to appear on cooling, the distribution of the relaxation times is symmetrically shaped. On cooling, the permittivity and loss spectra strongly broaden and slow down. The g(τ) function becomes asymmetrically shaped and the second maximum appears. The width of the g(τ) function is calculated at different temperatures. The shortest relaxation time is of the order of 10−12 s and it remains almost temperature independent. The longest relaxation time diverges according to Vogel–Fulcher law.