Submit to Minerals Review for Minerals Propose a Special Issue

Journal Menu

Journal Browser

NMR Spectroscopy in Mineralogy and Crystal Structures

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Minerals (ISSN 2075-163X). This special issue belongs to the section "Crystallography and Physical Chemistry of Minerals & Nanominerals".

Deadline for manuscript submissions: closed (23 June 2022) | Viewed by 12935

Share This Special Issue

Special Issue Editors

Dr. Luis Sánchez-Muñoz

E-Mail Website
Guest Editor

Museo Nacional de Ciencias Naturales (CSIC), Jose Gutierrez Abascal 2, 28006 Madrid, Spain
Interests: NMR; mineralogy; crystallography; meteorites; feldspars; pegmatites
Special Issues, Collections and Topics in MDPI journals

Dr. Pierre Florian

E-Mail Website
Guest Editor

CNRS, CEMHTI UPR3079, University of Orléans, F-45071 Orléans, France
Interests: solid-state NMR; organic and inorganic materials; very high temperature

Special Issue Information

Dear Colleagues,

Solid State Nuclear Magnetic Resonance (NMR) spectroscopy is unquestionably one of the most useful experimental techniques for the research of the local structures of minerals and crystalline solids, having different order-disorder states and solid solutions configurations. NMR is an alternative and complementary approach for the characterization of crystal structures to the reciprocal-space techniques. Whereas diffraction techniques are able to determine long-range atomic order as periodicity following the conventional lattice model, NMR techniques can also investigate medium- and short-range polyatomic order schemes, not only in ordered compounds but also in minerals with a low crystallinity and also in amorphous compounds, including feldspars, clay minerals, amphiboles, zeolites etc. NMR mineralogy has been a subject of intensive research along the 20^th Century in many minerals. But new methodologies are now derived from much more modern technological innovations, and thus novel methods are available for the study of atomic coordinations, spectroscopically-distinct crystal sites, order-disorder phenomena, atomic mobility, and the structural role of protons in several structural configurations as water molecules and also as –OH groups, including minerals with paramagnetic impurities, with a more detailed capability than never before. Therefore, the NMR technique is opening a new possibility to describe and explain the solid state in Nature, in a complementary approach to that from synthetic materials, based on the local configurations of atoms that develop or do not develop extended periodic arrangements. This new structural model can be derived from the research of the natural diversity of the crystal structures in Minerals.

Dr. Luis Sánchez-Muñoz
Dr. Pierre Florian
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Minerals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

solid-state NMR spectroscopy
minerals
crystal structures
short-range order
medium-range order
protons

Published Papers (6 papers)

Download All Papers

Research

Jump to: Review

17 pages, 7916 KiB

Open AccessArticle

Local Structure and Protons in Non-Stoichiometric Pseudo-Cubic Pollucite Mineral by Multinuclear NMR

by Luis Sánchez-Muñoz, José-Ignacio Santos, William B. Simmons and Pierre Florian

Minerals 2022, 12(10), 1181; https://doi.org/10.3390/min12101181 - 20 Sep 2022

Cited by 1 | Viewed by 1251

Abstract

The pollucite structure is considered as a candidate ceramic crystalline matrix for the ceramic immobilization and long-term storage of ¹³⁵Cs and ¹³⁷Cs fission products, and thus, their structural characteristics have particular importance. However, its local structure has not been fully resolved from reciprocal-space techniques and infrared spectroscopy, and important discrepancies exist in the available literature. Two birefringent and non-stoichiometric pollucite specimens from Tanco pegmatite (Cs_0.83Na_0.20Al_1.13Si_2.56O₆) and from Mt. Mica pegmatite (Cs_0.94Na₀₁₈Al_1.23Si_2.78O₆), with powder X-ray diffraction patterns fully consistent with the cubic Ia-3d space-group symmetry, and with a very different degree of hydrothermal alteration, were used in this work. High-resolution magic-angle spinning multinuclear magnetic resonance (MAS NMR) spectroscopy, including ²⁹Si, ²⁷Al, ²³Na, ¹³³Cs, and ¹H spectra at 9.4 T, as well as ¹H, ²⁷Al, ²⁷Al{¹H} dipolar evolutions and ²⁷Al{²⁹Si} Heteronuclear Multiple Quantum Coherence (HMCQ) spectra at 17.6 T, has been used to investigate the local structure of pollucite and the role of protons. The ²⁹Si spectra suggest a local structure with a disordered Si/Al distribution in only one tetrahedral T site, but with a preference of Si atoms for Q⁴₁ (3Si,1Al) and Q⁴₂ (2Si,2Al) environments, in comparison with random and Loewenstein distributions, due to charge dispersion effects. However, the ²⁷Al{¹H} dipolar evolutions suggest two spectroscopically distinct T sites for Al atoms. The ²³Na and ¹³³Cs spectra indicate broad site distributions for these cavity cations. The anisotropic character of the long-range disordered pollucite structure, with a pseudo-cubic symmetry and lack of strict periodicity, can be explained from an incipient displacive transition to lower symmetry. These pollucite specimens are essentially anhydrous minerals despite the ¹H and the cross-polarization experiments suggesting that some protons exist in the structure as -OH groups, whereas water molecules were only found in relation to the phyllosilicate impurities from alteration in specimen Tanco and perhaps also as liquid water in fluid inclusions. Full article

(This article belongs to the Special Issue NMR Spectroscopy in Mineralogy and Crystal Structures)

► Show Figures

Figure 1

34 pages, 9597 KiB

Open AccessArticle

Order-Disorder in the Structures of Lithium Aluminosilicate Minerals by XRD and Multinuclear NMR

by Luis Sánchez-Muñoz, Jesús Sanz, Pierre Florian, Virginia Diez-Gómez, Marta Furio and Isabel Sobrados

Minerals 2022, 12(4), 427; https://doi.org/10.3390/min12040427 - 30 Mar 2022

Cited by 2 | Viewed by 2707

Abstract

The crystal structures of the lithium aluminosilicate minerals of the Li₂O–Al₂O₃–SiO₂ (LAS) system (Li_1−xAl_1−xSi_1+xO₄ system for 0.0 ≤ x ≤ 1.0), and bikitaite were determined by X-ray diffraction (XRD) in literature, suggesting several possible lattice models for each of the crystallized phases, because of the intrinsic experimental difficulties of this technique. Here, we correlate powder XRD patterns with Rietveld refinement of cell parameters and magic angle sample spinning multinuclear magnetic resonance (NMR) spectra, including ²⁹Si, ²⁷Al, ⁷Li, and ⁶Li spectroscopy at 7.05 T, 9.4 T, and 20 T. The aim is to select appropriate lattice models from short-range order schemes in the lithium aluminosilicate phases, from natural minerals and synthetic crystals from the crystallization of amorphous gel precursors by a ceramic route and also by hydrothermal high-pressure experiments. Solid solutions were found in α-quartz and α-cristobalite up to x ≥ 0.75, and in β-eucryptite and β-spodumene for 0.0 ≤ x ≤ 1.0, when the ceramic synthesis is at work. The local structures of these intermediate members of the β-eucryptite and β-spodumene solid-solution series have ²⁹Si NMR spectra consistent with the Loewenstein’s rule, i.e., they have short-range order but are strictly non-periodic structures. However, β-eucryptite LiAlSiO₄ end-member has a short-range structure compatible with the long-range order of the P6₄22 symmetry, when the crystallization is produced at hydrothermal conditions. The local structure of α-spodumene LiAlSi₂O₆ is consistent with the C2/c model. α-eucryptite LiAlSiO₄ shows a short-range structure as that suggested by the R-3 lattice model. Petalite LiAlSi₄O₁₀ has a local structure compatible with the P2/a space group. Finally, the ²⁹Si NMR spectra of bikitaite LiAlSi₂O₆·H₂O indicate a short-range structure well-suited with the P1 symmetry. These results are consistent with the Ostwald‘s rule of stages, forming a order-disorder sequence of increasing long-range order from the starting fully disordered solid gels, through crystalline pseudoperiodic structures in non-stoichiometric solid solution crystals that respect the Lowenstein’s rule, up to fully ordered crystals with short-range structures from NMR close to the long-range structures by XRD, as in the stoichiometric compounds found in some natural minerals. Full article

(This article belongs to the Special Issue NMR Spectroscopy in Mineralogy and Crystal Structures)

► Show Figures

Figure 1

13 pages, 2549 KiB

Open AccessArticle

Insight into the Crystal Structures and Physical Properties of the Uranium Borides UB_1.78±0.02, UB_3.61±0.041 and UB_11.19±0.13

by Laura Martel, Thibault Charpentier, Pedro Amador Cedran, Chris Selfslag, Mohamed Naji, Jean-Christophe Griveau, Eric Colineau and Rachel Eloirdi

Minerals 2022, 12(1), 29; https://doi.org/10.3390/min12010029 - 24 Dec 2021

Viewed by 2200

Abstract

In this study we reported the synthesis of three polycrystalline uranium borides UB_1.78±0.02, UB_3.61±0.041, and UB_11.19_±0.13 and their analyses using chemical analysis, X-ray diffraction, SQUID magnetometry, solid-state NMR, and Fourier transformed infrared spectroscopy. We discuss the effects of stoichiometry deviations on the lattice parameters and magnetic properties. We also provide their static and MAS-NMR spectra showing the effects of the 5f-electrons on the ¹¹B shifts. Finally, the FTIR measurements showed the presence of a local disorder. Full article

(This article belongs to the Special Issue NMR Spectroscopy in Mineralogy and Crystal Structures)

► Show Figures

Figure 1

18 pages, 35347 KiB

Open AccessArticle

NMR Spectral Characteristics of Ultrahigh Pressure High Temperature Impact Glasses of the Giant Kara Crater (Pay-Khoy, Russia)

by Vladimir Lyutoev, Tatyana Shumilova, Anton Mazur and Peter Tolstoy

Minerals 2021, 11(12), 1418; https://doi.org/10.3390/min11121418 - 15 Dec 2021

Viewed by 2088

Abstract

In this study, we carried out the analysis of the impact melt vein glasses from the Kara impact crater (Russia) in comparison to low-pressure impact melt glasses (tektites) of the Zhamanshin crater (Kazakhstan). ²⁷Al, ²³Na, and ²⁹Si MAS NMR spectra of the samples of these glasses were analyzed. The samples of the natural glass contained inclusions of crystalline phases, paramagnetic elements that greatly complicate and distort the NMR signals from the glass phase itself. Taking into account the Mossbauer distribution of Fe in these glasses, the analysis of the spectra of MAS NMR of glass network-former (Si, Al) and potential network-modifiers (Na) of nuclei leads to the conclusion that the Kara impact melt vein glasses are characterized by complete polymerization of (Si,Al)O₄ tetrahedral structural units. The NMR features of the glasses are consistent with the vein hypothesis of their formation under conditions of high pressures and temperatures resulting in their fluidity, relatively slow solidification with partial melt differentiation, polymerization, and precipitation of mineral phases as the impact melt cools. The 70 Ma stability of the Kara impact vein glass can be explained by the stabilization of the glass network with primary fine-dispersed pyroxene and coesite precipitates and by the high polymerization level of the impact glass. Full article

(This article belongs to the Special Issue NMR Spectroscopy in Mineralogy and Crystal Structures)

► Show Figures

Figure 1

Review

Jump to: Research

60 pages, 13465 KiB

Open AccessEditor’s ChoiceReview

Order–Disorder Diversity of the Solid State by NMR: The Role of Electrical Charges

by Luis Sánchez-Muñoz, Pierre Florian, Zhehong Gan and Francisco Muñoz

Minerals 2022, 12(11), 1375; https://doi.org/10.3390/min12111375 - 29 Oct 2022

Viewed by 1775

Abstract

The physical explanations and understanding of the order–disorder phenomena in the solid state are commonly inferred from the experimental capabilities of the characterization techniques. Periodicity is recorded according to the averaging procedure of the conventional reciprocal-space techniques (RSTs) in many solids. This approach gives rise to a sharp trimodal view including non-crystalline or amorphous compounds, aperiodic crystals and periodic crystals. However, nuclear magnetic resonance (NMR) spectroscopy offers an alternative approach that is derived from the distinct character of the measurements involved at the local scale. Here, we present a sequence of progressive order–disorder states, from amorphous structures up to fully ordered mineral structures, showing the great diversity existing in the solid state using multinuclear NMR spectroscopy. Some examples in glasses and products of their crystallization are used, as well as several minerals (including beryl-group and feldspar-group minerals) at magnetic fields up to 35.2 T, and some examples from literature. This approach suggests that the solid state is a dynamic medium, whose behavior is due to atomic adjustments from local compensation of electrical charges between similar structural states, which explains Ostwald’s step rule of successive reactions. In fully ordered feldspar minerals, we propose that the electronic structure of the elements of the cavity site is involved in bonding, site morphology and feldspar topology. Furthermore, some implications are derived about what is a mineral structure from the point of view of the NMR experiments. They open the possibility for the development of the science of NMR Mineralogy. Full article

(This article belongs to the Special Issue NMR Spectroscopy in Mineralogy and Crystal Structures)

► Show Figures

Figure 1

18 pages, 2284 KiB

Open AccessReview

Pascoite Minerals and Potential Application of NMR Spectroscopy

by Craig C. McLauchlan, Beth Trent-Ringler and Debbie C. Crans

Minerals 2022, 12(8), 980; https://doi.org/10.3390/min12080980 - 01 Aug 2022

Cited by 1 | Viewed by 1826

Abstract

The 20 minerals encompassing the pascoite family of decavanadate isopolyanion-containing [V₁₀O₂₈]⁶⁻ minerals include a few minerals, such as rakovanite, that have been described as containing a protonated decavanadate anion. Rakovanite was originally assigned the formula Na₃[H₃V₁₀O₂₈]•15H₂O and now is redefined with an ideal formula (NH₄)₃Na₃[V₁₀O₂₈]•12H₂O. Nuclear magnetic resonance (NMR) and particularly ⁵¹V NMR spectroscopy is an informative method used to describe the protonation state and speciation in both solid and solution states of materials in the chemical and life sciences. However, ⁵¹V NMR spectroscopy has not yet been used experimentally to distinguish the protonation state of the decavanadate ion of leaching solutions and thus contributing to the discussion regarding the controversial protonation states of decavanadate ions in gunterite, rakovanite, and nashite. In contrast, the morphology and crystal structure for apatites, vanadinite, pyromorphite, and mimetite was related to ²⁰⁷Pb NMR chemical shifts, assisting in describing the local environments of these minerals. NMR spectroscopy could be a useful method if used in the future for decavanadate-containing minerals. Currently, partial reduction of two Pascoite minerals (caseyite and nashite) is proposed and accordingly could now effectively be investigated using a different magnetic resonance technique, EPR spectroscopy. Full article

(This article belongs to the Special Issue NMR Spectroscopy in Mineralogy and Crystal Structures)

► Show Figures