Pressure-induced structural changes in Eu-doped CaCO3 have been studied by time-resolved optical fluorescence spectroscopy and by total X-ray scattering combined with a pair distribution function analysis. Time-resolved fluorescence measurements are ideally suited to distinguish between calcitic and aragonitic local environments around the Eu-ions. We show that at ambient temperature calcite transforms at ∼10 GPa into an amorphous phase which locally has an aragonitic structure. This local structure is maintained on pressure release. The decay times of aragonite and the amorphous phase with a locally aragonitic structure are substantially longer than those of calcite.

You do not have access to this content, please speak to your institutional administrator if you feel you should have access.