Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function Analyses
The crystal structure of moganite from the Mogán formation on Gran Canaria has been re-investigated using high-resolution synchrotron X-ray diffraction (XRD) and X-ray/neutron pair distribution function (PDF) analyses. Our study for the first time reports the anisotropic atomic displacement paramete...
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MDPI AG
2021-03-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/11/3/272 |
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| author | Seungyeol Lee Huifang Xu Hongwu Xu Joerg Neuefeind |
| author_facet | Seungyeol Lee Huifang Xu Hongwu Xu Joerg Neuefeind |
| author_sort | Seungyeol Lee |
| collection | DOAJ |
| description | The crystal structure of moganite from the Mogán formation on Gran Canaria has been re-investigated using high-resolution synchrotron X-ray diffraction (XRD) and X-ray/neutron pair distribution function (PDF) analyses. Our study for the first time reports the anisotropic atomic displacement parameters (ADPs) of a natural moganite. Rietveld analysis of synchrotron XRD data determined the crystal structure of moganite with the space group <i>I</i>2/<i>a</i>. The refined unit-cell parameters are <i>a</i> = 8.7363(8), <i>b</i> = 4.8688(5), <i>c</i> = 10.7203(9) Å, and β = 90.212(4)°. The ADPs of Si and O in moganite were obtained from X-ray and neutron PDF analyses. The shapes and orientations of the anisotropic ellipsoids determined from X-ray and neutron measurements are similar. The anisotropic ellipsoids for O extend along planes perpendicular to the Si-Si axis of corner-sharing SiO<sub>4</sub> tetrahedra, suggesting precession-like movement. Neutron PDF result confirms the occurrence of OH over some of the tetrahedral sites. We postulate that moganite nanomineral is stable with respect to quartz in hypersaline water. The ADPs of moganite show a similar trend as those of quartz determined by single-crystal XRD. In short, the combined methods can provide high-quality structural parameters of moganite nanomineral, including its ADPs and extra OH position at the surface. This approach can be used as an alternative means for solving the structures of crystals that are not large enough for single-crystal XRD measurements, such as fine-grained and nanocrystalline minerals formed in various geological environments. |
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| last_indexed | 2024-03-09T05:07:32Z |
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| spelling | doaj.art-efb907b48e4442abbebbe1b9801f87482023-12-03T12:53:22ZengMDPI AGMinerals2075-163X2021-03-0111327210.3390/min11030272Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function AnalysesSeungyeol Lee0Huifang Xu1Hongwu Xu2Joerg Neuefeind3Department of Geoscience, University of Wisconsin–Madison, Madison, WI 53706, USADepartment of Geoscience, University of Wisconsin–Madison, Madison, WI 53706, USAEarth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USANeutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USAThe crystal structure of moganite from the Mogán formation on Gran Canaria has been re-investigated using high-resolution synchrotron X-ray diffraction (XRD) and X-ray/neutron pair distribution function (PDF) analyses. Our study for the first time reports the anisotropic atomic displacement parameters (ADPs) of a natural moganite. Rietveld analysis of synchrotron XRD data determined the crystal structure of moganite with the space group <i>I</i>2/<i>a</i>. The refined unit-cell parameters are <i>a</i> = 8.7363(8), <i>b</i> = 4.8688(5), <i>c</i> = 10.7203(9) Å, and β = 90.212(4)°. The ADPs of Si and O in moganite were obtained from X-ray and neutron PDF analyses. The shapes and orientations of the anisotropic ellipsoids determined from X-ray and neutron measurements are similar. The anisotropic ellipsoids for O extend along planes perpendicular to the Si-Si axis of corner-sharing SiO<sub>4</sub> tetrahedra, suggesting precession-like movement. Neutron PDF result confirms the occurrence of OH over some of the tetrahedral sites. We postulate that moganite nanomineral is stable with respect to quartz in hypersaline water. The ADPs of moganite show a similar trend as those of quartz determined by single-crystal XRD. In short, the combined methods can provide high-quality structural parameters of moganite nanomineral, including its ADPs and extra OH position at the surface. This approach can be used as an alternative means for solving the structures of crystals that are not large enough for single-crystal XRD measurements, such as fine-grained and nanocrystalline minerals formed in various geological environments.https://www.mdpi.com/2075-163X/11/3/272moganitequartzanisotropic atomic displacement parametersynchrotron X-ray diffractionneutron scatteringpair distribution function analysis |
| spellingShingle | Seungyeol Lee Huifang Xu Hongwu Xu Joerg Neuefeind Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function Analyses Minerals moganite quartz anisotropic atomic displacement parameter synchrotron X-ray diffraction neutron scattering pair distribution function analysis |
| title | Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function Analyses |
| title_full | Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function Analyses |
| title_fullStr | Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function Analyses |
| title_full_unstemmed | Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function Analyses |
| title_short | Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function Analyses |
| title_sort | crystal structure of moganite and its anisotropic atomic displacement parameters determined by synchrotron x ray diffraction and x ray neutron pair distribution function analyses |
| topic | moganite quartz anisotropic atomic displacement parameter synchrotron X-ray diffraction neutron scattering pair distribution function analysis |
| url | https://www.mdpi.com/2075-163X/11/3/272 |
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