TY - JOUR

T1 - Structure evolution of fluorapophyllite-(K) under high pressure

AU - Seryotkin, Yurii V.

AU - Ignatov, Mark A.

N1 - This work was supported by Russian Science Support Foundation [grant number 22-27-00235]. We thank two anonymous reviewers for their comprehensive remarks. X-ray experiments were done using the equipment of Research and Education Centre ‘Molecular Design and Ecologically Safe Technologies’ at NSU.

PY - 2023

Y1 - 2023

N2 - The high pressure structural evolution of a natural fluorapophyllite-(K) K0.70(NH4)0.20 Ca3.97Na0.07[Al0.04Si7.96O20]F0.99·(H2O)8.05, Z = 2, a = 8.9757(2), c = 15.7920(2) Å, space group P4/mnc, from Nidym river, East Siberia, Russia, compressed in penetrating (ethanol:water 4:1 mixture) and non-penetrating (paraffin oil) media up to 4.7 GPa, was studied by single-crystal X-ray diffraction with a diamond anvil cell. The compressibility is identical in both media. At the initial stage the compression proceeds mainly within the plane (xy) and less along the z-axis; above 3 GPa the compression becomes almost isometric. Within the whole pressure range there are no signs of the symmetry lowering. The main pressure-induced effect on the tetrahedral layer consists in a cooperative rotation of the 4-fold rings, which provides the structure compression within the (xy) plane. The compression along the z-axis proceeds through the shortening of the interlayer distance, whereas the thickness of silicate layer remains almost unchanged.

AB - The high pressure structural evolution of a natural fluorapophyllite-(K) K0.70(NH4)0.20 Ca3.97Na0.07[Al0.04Si7.96O20]F0.99·(H2O)8.05, Z = 2, a = 8.9757(2), c = 15.7920(2) Å, space group P4/mnc, from Nidym river, East Siberia, Russia, compressed in penetrating (ethanol:water 4:1 mixture) and non-penetrating (paraffin oil) media up to 4.7 GPa, was studied by single-crystal X-ray diffraction with a diamond anvil cell. The compressibility is identical in both media. At the initial stage the compression proceeds mainly within the plane (xy) and less along the z-axis; above 3 GPa the compression becomes almost isometric. Within the whole pressure range there are no signs of the symmetry lowering. The main pressure-induced effect on the tetrahedral layer consists in a cooperative rotation of the 4-fold rings, which provides the structure compression within the (xy) plane. The compression along the z-axis proceeds through the shortening of the interlayer distance, whereas the thickness of silicate layer remains almost unchanged.

KW - Apophyllite group

KW - Fluorapophyllite-(K)

KW - High pressure

KW - Structural evolution

KW - X-ray diffraction

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85168443947&origin=inward&txGid=1de413ca54b6acb46951b0ccf1bf1c42

UR - https://www.mendeley.com/catalogue/fae678d5-e6f0-3d9a-936d-458118403ce5/

U2 - 10.1080/08957959.2023.2248357

DO - 10.1080/08957959.2023.2248357

M3 - Article

VL - 43

SP - 279

EP - 292

JO - High Pressure Research

JF - High Pressure Research

SN - 0895-7959

IS - 4

ER -