Pressure-induced amorphization of Na2Al2Si3O10· 2H2O and KAlSi2O6zeolites

✍ Scribed by Goryainov, Sergei

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 198 KB
• Volume: 202
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200409094

✦ Synopsis

Abstract

Pressure‐induced amorphization has been observed in two zeolites, natrolite Na~2~Al~2~Si~3~O~10~ · 2H~2~O and leucite KAlSi~2~O~6~. Using Raman microprobe, amorphized samples were analysed in situ at high pressures at compression in methanol–ethanol medium in diamond anvil cell and also after release of pressure. Before amorphization, one crystal‐to‐crystal phase transition was observed in each zeolite. It was shown for Na~2~Al~2~Si~3~O~10~ · 2H~2~O that the transition from crystalline to amorphous phase is partially reversible for compression to the peak pressure in the range of ∼7–10 GPa and practically irreversible above ∼10 GPa. Surprising, the dehydrated crystal KAlSi~2~O~6~ exhibited very high quasi‐stability, at compression up to 16 GPa for one day. Long time compression (for 15 days) led to almost full amorphization of KAlSi~2~O~6~. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)