High-pressure behavior and crystal-fluid interaction under extreme conditions in paulingite [PAU-topology]

Autor(en)
Giacomo Diego Gatta, Katharina Sarah Scheidl, Thomas Pippinger, Roman Skala, Yongjae Lee, Ronald Miletich-Pawliczek
Abstrakt

The compressional behavior and the P-induced crystal-fluid interaction of a natural paulingite-K have been explored on the basis of in-situ single-crystal and powder X-ray diffraction, and in-situ single-crystal Raman spectroscopy with a diamond anvil cell and a series of diverse pressure-transmitting fluids (i.e., silicone-oil, methanol:ethanol = 4:1, methanol:ethanol:water = 16:3:1). No evidence of any phase transition was obsd. within the P-range investigated, independent on the used P-fluids. The compressional behavior of paulingite is significantly different in response to the different nature of the P-fluids. A drastically lower compressibility is obsd. when the zeolite is compressed in methanol:ethanol or, even more noticeably, in methanol:ethanol:water mix. We ascribe this phenomenon to the different crystal-fluid interaction at high pressure: (1) silicone-oil is a "non-penetrating" P-medium, because of its polymeric nature, whereas (2) methanol-ethanol and water are "penetrating" P-fluids. The P-induced penetration processes appear to be completely reversible on the basis of the X-ray diffraction data alone. The Raman spectra collected after the high-pressure expts. show, unambiguously, that a residual fraction of methanol (and/or ethanol and probably even extra H2O) still resides in the zeolitic sub-nanocavities; such mols. are spontaneously released after a few days at atm. pressure. The actual compressibility of paulingite-K is that obtained by the compression expt. in silicone-oil, with an isothermal bulk modulus K0 = ß-10 = 18.0(1.1) GPa. Paulingite appears to be one of the softest zeolite ever found.

Organisation(en)
Institut für Mineralogie und Kristallographie
Externe Organisation(en)
Università degli Studi di Milano-Bicocca, Charles University Prague, Yonsei University
Journal
Microporous and Mesoporous Materials
Band
206
Seiten
34-41
Anzahl der Seiten
8
ISSN
1387-1811
DOI
https://doi.org/10.1016/j.micromeso.2014.11.031
Publikationsdatum
12-2014
Peer-reviewed
Ja
ÖFOS 2012
105116 Mineralogie, 104011 Materialchemie, 105113 Kristallographie
Schlagwörter
ASJC Scopus Sachgebiete
Condensed Matter Physics, Mechanics of Materials, Allgemeine Chemie, Allgemeine Materialwissenschaften
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/498d4af6-f0c8-474a-aa87-2941fa074dbb