Structural modifications induced by high pressure in scolecite and heulandite: in-situ synchrotron X-ray powder diffraction study

摘要

We present an in-situ synchrotron X-ray powder diffraction study on the compressibilityrnand the pressure-induced structural modifications in the two natural zeolites scolecite andrnheulandite. The experiments were continued up to the amorphization of the zeolites. Therncell parameter refinements were carried out up to 7.5 GPa and 6 GPa for scolecite andrnheulandite, respectively. Unlike heulandite, a slight increase of compressibility withrnpressure is observed in scolecite. The HP-induced deformations of both zeolites can berninterpreted on the basis of the mechanisms observed during the dehydration processes ofrnthe two zeolites, even if the degree of deformation is different in the two processes. Thernamorphization process is reversible only for heulandite and occurs at a lower pressurerncompared with scolecite.