On the high-pressure behavior of gobbinsite, the natural counterpart of the synthetic zeolite Na–P2
Articolo
Data di Pubblicazione:
2012
Citazione:
On the high-pressure behavior of gobbinsite, the natural counterpart of the synthetic zeolite Na–P2 / G.D. Gatta, P. Lotti, F. Nestola, D. Pasqual. - In: MICROPOROUS AND MESOPOROUS MATERIALS. - ISSN 1387-1811. - 163(2012 Nov), pp. 259-269.
Abstract:
An in situ high-pressure single-crystal X-ray diffraction study of gobbinsite, the natural counterpart of the
synthetic zeolite Na–P2, was carried out up to 4.3 GPa. No evidence of amorphization was observed
within pressure-range investigated. Using a non-penetrating P-medium, two changes of the elastic
behavior occur: the first at 1.1–1.3 GPa and the second at 2.7–3.2 GPa. Birch-Murnaghan equations of
state truncated to the second order were used to fit the experimental P–V data within the three P-ranges
(i.e. 0.0001–1.1, 1.3–2.7 and 3.2–4.3 GPa), giving the following isothermal bulk moduli (KV0): 46.3(9),
52(8) and 28(6) GPa, respectively. The unit-cell compression is significantly anisotropic. In response to
the applied pressure, the 8-membered ring channel parallel to [100] undergoes a significant increase
of ellipticity, whereas the channel parallel to [010] undergoes a shrinking towards a circular shape at
PP1.3 GPa. A partial re-organization of the H2O sites occurs between 1.1 and 1.3 GPa, and new framework
deformational modes onset at PP3.2 GPa, coupled with a change in the coordination environment
of the extraframework cations.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
compressibility; gobbinsite; high pressure; structure evolution; zeolites-P
Elenco autori:
G.D. Gatta, P. Lotti, F. Nestola, D. Pasqual
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