The high-pressure behavior of a synthetic mordenite- Na (space group: Cmcm or Cmc21) was studied by in situ single-crystal synchrotron X-ray diffraction with a diamond anvil cell up to 9.22(7) GPa. A phase transition, likely displacive in character, occurred between 1.68(7) and 2.70(8) GPa, from a C-centered to a primitive space group: possibly Pbnm, Pbnn or Pbn21. Fitting of the experimental data with III-BM equations of state allowed to describe the elastic behavior of the high-pressure polymorph with a primitive lattice. A very high volume compressibility [KV0 = 25(2) GPa, βV0 = 1/KV0 = 0.040(3) GPa–1; KV′ = (∂KV/∂P)T = 2.0(3)], coupled with a remarkable elastic anisotropy (βb > > βc > βa), was found. Interestingly, the low-P and high-P polymorphs show the same anisotropic compressional scheme. A structure collapse was not observed up to 9.22(7) GPa, even though a strong decrease of the number of observed reflections at the highest pressures suggests an impending amorphization. The structure refinements performed at room-P, 0.98(2) and 1.68(7) GPa allowed to describe, at a first approximation, the mechanisms that govern the framework deformation in the low-P regime: the bulk compression is strongly accommodated by the increase of the ellipticity of the large 12-membered ring channels running along .
High-pressure behavior of synthetic mordenite-Na: an in situ single-crystal synchrotron X-ray diffraction study / P. Lotti, G.D. Gatta, M. Merlini, H. Liermann. - In: ZEITSCHRIFT FUR KRISTALLOGRAPHIE. - ISSN 0044-2968. - 230:4(2015), pp. 201-211.
|Titolo:||High-pressure behavior of synthetic mordenite-Na: an in situ single-crystal synchrotron X-ray diffraction study|
LOTTI, PAOLO (Primo)
GATTA, GIACOMO DIEGO (Secondo)
MERLINI, MARCO (Penultimo)
|Parole Chiave:||Elastic behavior; High pressure; Mordenite; Phase transition; Single-crystal synchrotron X-ray diffraction|
|Settore Scientifico Disciplinare:||Settore GEO/09 - Georisorse Miner.Appl.Mineral.-Petrogr.per l'amb.e i Beni Cul|
Settore GEO/06 - Mineralogia
|Data di pubblicazione:||2015|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1515/zkri-2014-1796|
|Appare nelle tipologie:||01 - Articolo su periodico|
File in questo prodotto:
|MOR-HP-ZfK.pdf||Publisher's version/PDF||Administrator Richiedi una copia|
|Mordenite-HP-Lotti_et_al-R1.pdf||Versione accettata dall'editore per la stampa||Post-print, accepted manuscript ecc. (versione accettata dall'editore)||Open Access Visualizza/Apri|