A moganite-type phase in the silica analog phosphorus oxynitride

Centre National de la Recherche Scientifique, Laboratoire de Physico-Chimie des Materiaux, Meudon, France

A new polymorph of phosphorus oxynitride (PON) a silica analog has been recovered at ambient pressure by quenching after a treatment at 850 degrees C under a pressure of 2.5 GPa using cristobalite- or quartz-type phases as starting materials. This PON polymorph is a thermodynamically stable phase with its own stability field in a P-T diagram. The structure of this PON phase was refined by the Rietveld method from an X-ray powder diffractogram. It is isostructural with "moganite" (SiO ₂ ). The discovery of this PON polymorph should stimulate a renewed interest in the occurrence of this phase in the silica system, because "moganite" may have a small but defined P-T stability field. These results confirm the structure of "moganite" as a new structure-type in AX ₂ compounds.

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This article has been cited by other articles:

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