J. Phys. IV France 128 (2005) 127-131
Distribution of relaxation times in PMN single crystalR. Grigalaitis1, J. Banys1, A. Kania2 and A. Slodczyk2
1 Faculty of Physics, Vilnius University, Sauletekio 9, Vilnius, Lithuania
2 August Chelkowski Institute of Physics, University of Silesia, Uniwersytetska 4, 40-007 Katowice, Poland
The dielectric permittivity of PMN single crystal was measured in the frequency range from 20 Hz to 3 GHz. Dielectric dispersion was observed in all investigated frequency range. From the frequency dependence of the real and imaginary parts of dielectric permittvity, the distribution of relaxation times was calculated. The low frequency limit of the distribution of the relaxation times diverge according to the Vogel - Fulcher law with the freezing temperature T0 = 228 K, which is in good agreement with mean relaxation time temperature dependence obtained from Cole - Cole equation. Broadening of the relaxation time distribution function at low temperatures indicates the existence of two different components making contribution to the total dielectric spectrum of PMN.
© EDP Sciences 2005