Correlation of dielectric dispersion with distributed Curie temperature in relaxor ferroelectrics

The fascinating dielectric property of relaxor ferroelectrics is investigated on the basis of phase-transition dynamics within the mean-field theory. With a power-law distribution of the Curie temperature for the second order phase transition ferroelectrics, the complex dielectric permittivity is derived. The result shows that the modified Curie-Weiss relation in the paraelectric phase follows the power-law distribution directly. The significant conclusion is that the rediscovered distributed Curie temperature can describe the universal dielectric dispersion for both real part and imaginary part of dielectric permittivity with temperature and frequency in relaxor ferroelectrics, and it conforms well to experimental results.