Moessbauer investigations of lattice dynamics in (SnTe)x(PbSe)1-x system with the help of 119Sn nuclei

By means of Moessbauer effect the lattice dynamics of narrow gap semiconductor solid solutions (SnTe)x(PbSe)1-x, when x=0.9, 0.6, 0.4 has been studied with the help of the 119Sn nuclei in the temperature range from 130 to 300 K. The temperature dependences of absolute Moessbauer effect probabilities as well as effective Debye temperatures have been obtained. Mean-square deviations of tin atoms from equilibrium have been calculated. In the studied temperature range the Debye model has been shown to be applicable for the description of the oscillation spectrum of the system with the exception of the concentrations, at which zone inversion takes place. It has been shown that with the increase of the PbSe quantity the Debye temperature slightly decreases, and mean-square amplitudes of tin atom oscillations enhance. Deviation of the temperature dependence of the isomer shift from the theoretical value has been explained by the possible manifestation of the electron-phonon interaction