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Mohammadi H, Zeidler A, Youngman RE, Fischer HE, Salmon PS. Pressure dependent structure of amorphous magnesium aluminosilicates: The effect of replacing magnesia by alumina at the enstatite composition. J Chem Phys 2024; 160:064501. [PMID: 38341794 DOI: 10.1063/5.0189392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/07/2024] [Indexed: 02/13/2024] Open
Abstract
The effect of replacing magnesia by alumina on the pressure-dependent structure of amorphous enstatite was investigated by applying in situ high-pressure neutron diffraction with magnesium isotope substitution to glassy (MgO)0.375(Al2O3)0.125(SiO2)0.5. The replacement leads to a factor of 2.4 increase in the rate-of-change of the Mg-O coordination number with pressure, which increases from 4.76(4) at ambient pressure to 6.51(4) at 8.2 GPa, and accompanies a larger probability of magnesium finding bridging oxygen atoms as nearest-neighbors. The Al-O coordination number increases from 4.17(7) to 5.24(8) over the same pressure interval at a rate that increases when the pressure is above ∼3.5 GPa. On recovering the glass to ambient conditions, the Mg-O and Al-O coordination numbers reduce to 5.32(4) and 4.42(6), respectively. The Al-O value is in accordance with the results from solid-state 27Al nuclear magnetic resonance spectroscopy, which show the presence of six-coordinated aluminum species that are absent in the uncompressed material. These findings explain the appearance of distinct pressure-dependent structural transformation regimes in the preparation of permanently densified magnesium aluminosilicate glasses. They also indicate an anomalous minimum in the pressure dependence of the bulk modulus with an onset that suggests a pressure-dependent threshold for transitioning between scratch-resistant and crack-resistant material properties.
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Affiliation(s)
| | - Anita Zeidler
- Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom
| | - Randall E Youngman
- Science and Technology Division, Corning Incorporated, Corning, New York 14831, USA
| | - Henry E Fischer
- Institut Laue Langevin, 71 Avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Philip S Salmon
- Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom
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Yamashita K, Nakayama K, Komatsu K, Ohhara T, Munakata K, Hattori T, Sano-Furukawa A, Kagi H. The hydrogen-bond network in sodium chloride tridecahydrate: analogy with ice VI. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2023; 79:414-426. [PMID: 37703290 DOI: 10.1107/s2052520623007199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 08/16/2023] [Indexed: 09/15/2023]
Abstract
The structure of a recently found hyperhydrated form of sodium chloride (NaCl·13H2O and NaCl·13D2O) has been determined by in situ single-crystal neutron diffraction at 1.7 GPa and 298 K. It has large hydrogen-bond networks and some water molecules have distorted bonding features such as bifurcated hydrogen bonds and five-coordinated water molecules. The hydrogen-bond network has similarities to ice VI in terms of network topology and disordered hydrogen bonds. Assuming the equivalence of network components connected by pseudo-symmetries, the overall network structure of this hydrate can be expressed by breaking it down into smaller structural units which correspond to the ice VI network structure. This hydrogen-bond network contains orientational disorder of water molecules in contrast to the known salt hydrates. An example is presented here for further insights into a hydrogen-bond network containing ionic species.
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Affiliation(s)
- Keishiro Yamashita
- Geochemical Research Center, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kazuya Nakayama
- Geochemical Research Center, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kazuki Komatsu
- Geochemical Research Center, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takashi Ohhara
- J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Ibaraki 319-1195, Japan
| | - Koji Munakata
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), IQBRC Building, 162-1 Shirakata, Tokai, Naka, Ibaraki 319-1106, Japan
| | - Takanori Hattori
- J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Ibaraki 319-1195, Japan
| | - Asami Sano-Furukawa
- J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Ibaraki 319-1195, Japan
| | - Hiroyuki Kagi
- Geochemical Research Center, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Effect of alkali metal ions on water structure: insights into the pressure-like effect. Struct Chem 2022. [DOI: 10.1007/s11224-022-02101-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Neutron scattering on an aqueous sodium chloride solution in the gigapascal pressure range. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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