Method of direct determination of relaxation time distribution function in glasses, relaxor and ferroelectric phases

Abstract

Experimental dielectric spectra ε*(ω) of many real materials (ceramics, for instance) usually differs from the curve ordered by Debye's law. This phenomenon is an intrinsic feature of that materials and is a consequence of relaxators (relaxing participles) distribution vs. frequency or of relaxators interactions. We have suggested and developed new method of direct determination of relaxation times distribution function (RTDF) Y(Ω) from experimental data ε*. So, experimental errors Δε in real dielectric spectra ε*(ω) were the main problem for previous approaches to the issue of RTDF determination. We solved this problem by using Tikhonov's regularization approach to build correct method of Y(Ω,T) determination from real experimental data ε*(ω) + Δε. Suggested method was tested on model dielectric spectra. Using this method we have obtained interesting results in the investigation of K_1−xLi_xTaO₃ -single crystals. Some of these results are present in this paper.