Investigation of the dielectric relaxation mechanisms for Pb(Fe_1/2Nb_1/2)O₃ single crystal based on the universal relaxation law

Large-sized multiferroics Pb(Fe1/2Nb1/2)O3 (PFN) single crystal was grown by Bridgeman method in order to understand the giant dielectric response by investigating the electrical conductivity and dielectric properties. The synchrotron radiation soft x-ray absorption spectrum revealed the valence states of Fe in PFN crystal. PFN exhibits semiconductor behaviors in the thermal active electrical conductivity investigation. Besides, the frequency-dependent dielectric constants were measured in the frequency range from 100 Hz to 1 MHz to study the dielectric relaxation behaviors. Two relaxation processes were found and described by Havriliak-Negami equation. The origin of dielectric relaxation in PFN with semiconductor characters was discussed based on the universal relaxation law for a dipolar system