Theory of dielectric absorption line shape in dielectrics and ferroelectrics

We present the theory of dielectric spectra allowing for homogeneous and in homogeneous broadening mechanisms contributions. The dielectric absorption line shape for oscillators with memory and Debye type relaxors with distrib ution or respectively, resonant frequencies and relaxation times (due to ra ndom electric fields distribution) has been calculated. The conditions of h ole burning observation are discussed. It is shown that the investigations of the inhomogeneously broadened line shape and width as well as hole burni ng can give valuable information about the distribution of random fields an d relaxation times. The latter seems to be extremely important for the diso rdered systems like supercooled liquids and relaxer ferroelectrics.