Pressure-induced structural evolution and elastic behaviour of Na6Cs2Ga6Ge6O24 · Ge(OH)6 variant of cancrinite

A synchrotron powder diffraction study

G. Diego Gatta, Yongjae Lee

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The elastic behaviour and the pressure (P) induced structural evolution of Na6Cs2Ga6Ge6O24 · Ge(OH)6, a synthetic compound isotypic with cancrinite (CAN topology), have been investigated up to 5.01(5) GPa by means of in situ X-ray synchrotron powder diffraction with a diamond anvil cell and using a nominally penetrating hydrous P-transmitting medium (methanol:ethanol:water = 16:3:1). No evidence of phase-transition was observed within the P-range investigated. The P-V data were fitted with a Murnaghan equation-of-state (M-EoS). The elastic parameters obtained, using the data weighted by the uncertainties in P-V, are: V0 = 757.16(7) Å3, KT0 = 36(2) GPa [KT0 = 1/β = -V0(∂P/∂V)P=0, where β is the volume compressibility coefficient] and K′ = (∂KT0/∂P) = 9(1). The elastic behaviour along the a and c axis was described with a "linearised" M-EoS. The refined parameters of the linearised M-EoS are: a0 = 13.0314(4) Å, KT0(a) = 40(2) [βj = -1/(3KT0(j)) = (1/l0j)(∂lj/∂P), where βj is the axial compressibility coefficient] and K′(a) = 11(1) for the a-axis; c0 = 5.1485(4) Å, KT0(c) = 31(1) GPa and K′(c) = 7.4(8) for the c-axis. The elastic anisotropy of Na6Cs2Ga6Ge6O24 · Ge(OH)6 is only marginal, being KT0(a): KT0(c) = 1.29:1. The configuration of the extra-framework content is basically maintained at high-pressure, without any major changes. The Ge(OH)6-polyhedron is strongly compressed in response to the applied pressure, but there is no evidence of further deformation. On the other hand the Na(O3OH3)-polyhedron and the large Cs-polyhedron appear to be compressed in a way to lessen the deformation with increasing pressures. Despite the use of a hydrous P-transmitting fluid for the HP-experiment and the large "free-diameters" of the channels in CAN framework, no evidence of superhydration effect was observed within the P-range investigated.

Original languageEnglish
Pages (from-to)51-58
Number of pages8
JournalMicroporous and Mesoporous Materials
Volume116
Issue number1-3
DOIs
Publication statusPublished - 2008 Dec 1

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polyhedrons
Synchrotrons
synchrotrons
compressibility
equations of state
Compressibility
Equations of state
diffraction
elastic anisotropy
coefficients
anvils
Diamond
ethyl alcohol
topology
methyl alcohol
diamonds
Methanol
Diamonds
Anisotropy
Ethanol

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials

Cite this

@article{784ede696ff64b20a1bfe0452c4c6f1a,
title = "Pressure-induced structural evolution and elastic behaviour of Na6Cs2Ga6Ge6O24 · Ge(OH)6 variant of cancrinite: A synchrotron powder diffraction study",
abstract = "The elastic behaviour and the pressure (P) induced structural evolution of Na6Cs2Ga6Ge6O24 · Ge(OH)6, a synthetic compound isotypic with cancrinite (CAN topology), have been investigated up to 5.01(5) GPa by means of in situ X-ray synchrotron powder diffraction with a diamond anvil cell and using a nominally penetrating hydrous P-transmitting medium (methanol:ethanol:water = 16:3:1). No evidence of phase-transition was observed within the P-range investigated. The P-V data were fitted with a Murnaghan equation-of-state (M-EoS). The elastic parameters obtained, using the data weighted by the uncertainties in P-V, are: V0 = 757.16(7) {\AA}3, KT0 = 36(2) GPa [KT0 = 1/β = -V0(∂P/∂V)P=0, where β is the volume compressibility coefficient] and K′ = (∂KT0/∂P) = 9(1). The elastic behaviour along the a and c axis was described with a {"}linearised{"} M-EoS. The refined parameters of the linearised M-EoS are: a0 = 13.0314(4) {\AA}, KT0(a) = 40(2) [βj = -1/(3KT0(j)) = (1/l0j)(∂lj/∂P), where βj is the axial compressibility coefficient] and K′(a) = 11(1) for the a-axis; c0 = 5.1485(4) {\AA}, KT0(c) = 31(1) GPa and K′(c) = 7.4(8) for the c-axis. The elastic anisotropy of Na6Cs2Ga6Ge6O24 · Ge(OH)6 is only marginal, being KT0(a): KT0(c) = 1.29:1. The configuration of the extra-framework content is basically maintained at high-pressure, without any major changes. The Ge(OH)6-polyhedron is strongly compressed in response to the applied pressure, but there is no evidence of further deformation. On the other hand the Na(O3OH3)-polyhedron and the large Cs-polyhedron appear to be compressed in a way to lessen the deformation with increasing pressures. Despite the use of a hydrous P-transmitting fluid for the HP-experiment and the large {"}free-diameters{"} of the channels in CAN framework, no evidence of superhydration effect was observed within the P-range investigated.",
author = "{Diego Gatta}, G. and Yongjae Lee",
year = "2008",
month = "12",
day = "1",
doi = "10.1016/j.micromeso.2008.03.010",
language = "English",
volume = "116",
pages = "51--58",
journal = "Microporous and Mesoporous Materials",
issn = "1387-1811",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - Pressure-induced structural evolution and elastic behaviour of Na6Cs2Ga6Ge6O24 · Ge(OH)6 variant of cancrinite

T2 - A synchrotron powder diffraction study

AU - Diego Gatta, G.

AU - Lee, Yongjae

PY - 2008/12/1

Y1 - 2008/12/1

N2 - The elastic behaviour and the pressure (P) induced structural evolution of Na6Cs2Ga6Ge6O24 · Ge(OH)6, a synthetic compound isotypic with cancrinite (CAN topology), have been investigated up to 5.01(5) GPa by means of in situ X-ray synchrotron powder diffraction with a diamond anvil cell and using a nominally penetrating hydrous P-transmitting medium (methanol:ethanol:water = 16:3:1). No evidence of phase-transition was observed within the P-range investigated. The P-V data were fitted with a Murnaghan equation-of-state (M-EoS). The elastic parameters obtained, using the data weighted by the uncertainties in P-V, are: V0 = 757.16(7) Å3, KT0 = 36(2) GPa [KT0 = 1/β = -V0(∂P/∂V)P=0, where β is the volume compressibility coefficient] and K′ = (∂KT0/∂P) = 9(1). The elastic behaviour along the a and c axis was described with a "linearised" M-EoS. The refined parameters of the linearised M-EoS are: a0 = 13.0314(4) Å, KT0(a) = 40(2) [βj = -1/(3KT0(j)) = (1/l0j)(∂lj/∂P), where βj is the axial compressibility coefficient] and K′(a) = 11(1) for the a-axis; c0 = 5.1485(4) Å, KT0(c) = 31(1) GPa and K′(c) = 7.4(8) for the c-axis. The elastic anisotropy of Na6Cs2Ga6Ge6O24 · Ge(OH)6 is only marginal, being KT0(a): KT0(c) = 1.29:1. The configuration of the extra-framework content is basically maintained at high-pressure, without any major changes. The Ge(OH)6-polyhedron is strongly compressed in response to the applied pressure, but there is no evidence of further deformation. On the other hand the Na(O3OH3)-polyhedron and the large Cs-polyhedron appear to be compressed in a way to lessen the deformation with increasing pressures. Despite the use of a hydrous P-transmitting fluid for the HP-experiment and the large "free-diameters" of the channels in CAN framework, no evidence of superhydration effect was observed within the P-range investigated.

AB - The elastic behaviour and the pressure (P) induced structural evolution of Na6Cs2Ga6Ge6O24 · Ge(OH)6, a synthetic compound isotypic with cancrinite (CAN topology), have been investigated up to 5.01(5) GPa by means of in situ X-ray synchrotron powder diffraction with a diamond anvil cell and using a nominally penetrating hydrous P-transmitting medium (methanol:ethanol:water = 16:3:1). No evidence of phase-transition was observed within the P-range investigated. The P-V data were fitted with a Murnaghan equation-of-state (M-EoS). The elastic parameters obtained, using the data weighted by the uncertainties in P-V, are: V0 = 757.16(7) Å3, KT0 = 36(2) GPa [KT0 = 1/β = -V0(∂P/∂V)P=0, where β is the volume compressibility coefficient] and K′ = (∂KT0/∂P) = 9(1). The elastic behaviour along the a and c axis was described with a "linearised" M-EoS. The refined parameters of the linearised M-EoS are: a0 = 13.0314(4) Å, KT0(a) = 40(2) [βj = -1/(3KT0(j)) = (1/l0j)(∂lj/∂P), where βj is the axial compressibility coefficient] and K′(a) = 11(1) for the a-axis; c0 = 5.1485(4) Å, KT0(c) = 31(1) GPa and K′(c) = 7.4(8) for the c-axis. The elastic anisotropy of Na6Cs2Ga6Ge6O24 · Ge(OH)6 is only marginal, being KT0(a): KT0(c) = 1.29:1. The configuration of the extra-framework content is basically maintained at high-pressure, without any major changes. The Ge(OH)6-polyhedron is strongly compressed in response to the applied pressure, but there is no evidence of further deformation. On the other hand the Na(O3OH3)-polyhedron and the large Cs-polyhedron appear to be compressed in a way to lessen the deformation with increasing pressures. Despite the use of a hydrous P-transmitting fluid for the HP-experiment and the large "free-diameters" of the channels in CAN framework, no evidence of superhydration effect was observed within the P-range investigated.

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U2 - 10.1016/j.micromeso.2008.03.010

DO - 10.1016/j.micromeso.2008.03.010

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EP - 58

JO - Microporous and Mesoporous Materials

JF - Microporous and Mesoporous Materials

SN - 1387-1811

IS - 1-3

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