Rayleigh scattering of Moessbauer radiation method used in dynamics studies of condensed matter

Rayleigh scattering of Moessbauer radiation is a less common technique used in the study of the properties of condensed matter. The detection of the scattered radiation via the nuclear resonance absorption, with an energy resolution of the order of 10-8 eV make this technique very sensitive to dynamics changes. The results of our studies by the Rayleigh scattering of the Moessbauer radiation on pyrolytic graphite (C) and rubidium tetrachlorozincate (Rb2ZnCl4) are reported. The contribution of the coherent inelastic scattering to the total intensity i C(002) is presented like a consequence of the coupling motions of C atoms in the hexagonal plane. The normal-incommensurate phase transition in Rb2ZnCl4 is discussed in connection with the photon-phonon interaction. (author)