Brillouin Scattering and Thermal Expansion of SnCl₂·2H₂O

Abstract

Brillouin scattering spectra and the thermal expansion of SnCl₂·2H₂O were experimentally studied over a temperature range covering the isomorphous transition at −55°C (T_c). The frequency shifts of the longitudinal phonon show an anomaly at the phase transition temperature for q⁄⁄[100], [001] and [101] but not for q⁄⁄[010]. The thermal expansions along the crystalline axes a^*, b and c show discontinuity at T_c.