Study of the purely ferroelastic phase transition in agr-Sb5O7lBY Raman spectroscopy

Zusammenfassung

The purely ferroelastic phase transition at 481 K of agr-Sb5O7I has been investigated by Raman scattering. In the ferroelastic phase a strongly damped soft mode was observed. The temperature variation of several lines, which disappear above Tc, shows that the phase transition is weakly discontinuous. The experimental results and the structural changes of the crystal may be explained by assuming a zone boundary soft mode in the paraelastic phase.