SHELL-MODEL LATTICE-DYNAMICS AND MOSSBAUER RECOILLESS FRACTION OF SNO

A lattice-dynamical study of the phonon-dispersion relation in tin mon oxide is presented in the framework of the shell model. The Mossbauer recoilless fraction f(T) has been evaluated over a wide range of tempe ratures. Except for a temperature-independent shift, the calculated va lues of - ln(f) are in good agreement with recent Mossbauer spectrosco py experiments on a highly textured powder sample. The phonon density of states shows two prominent bands with practically no mixed Sn and O characters, as identified from the ion-projected densities. The calcu lated mu(-2) moment of the spectrum is in accordance with the value ob tained from the measurements.