Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Structure of Rare-Earth Aluminosilicate Glasses Probed by Solid-State NMR Spectroscopy and Quantum Chemical Calculations
Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Aluminosilicate glasses incorporating rare earth elements feature highly beneficial physical and chemical properties, at the level beyond that accessible for compositions based on alkali and/or alkaline earth metals. Extraordinary hardness, high glass transition temperatures and indices of refraction, favorable coefficients of thermal expansion, as well as excellent chemical durability, result in many potential technological applications. However, in contrast to the systematically explored and commercially exploited aluminosilicate glasses that contain Na, K, and Ca elements, their rare earth counterparts were sparsely investigated, although exhibit several unique structural features.

This thesis explored the short- and medium-range structural organization of glasses belonging to the ternary RE2O3—Al2O3—SiO2 systems, where RE denotes one of the trivalent and diamagnetic rare earth metal ions of scandium (Sc), yttrium (Y), lanthanum (La), and lutetium (Lu). Comprehensive multinuclear solid-state nuclear magnetic resonance studies complemented with atomistic molecular dynamics computer simulations and quantum chemical calculations provided detailed insight into local environments of the glass networkforming elements (Si, Al), oxygen species, as well as the rare earth ions, thereby offering a deeper understanding of the glass structure.

Place, publisher, year, edition, pages
Stockholm: Department of Materials and Environmental Chemistry (MMK), Stockholm University , 2016.
National Category
Physical Chemistry
Research subject
Physical Chemistry
Identifiers
URN: urn:nbn:se:su:diva-129112ISBN: 978-91-7649-398-4 (print)OAI: oai:DiVA.org:su-129112DiVA: diva2:919657
Public defence
2016-06-07, De Geersalen, Geovetenskapens hus, Svante Arrhenius väg 14, Stockholm, 14:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.

Available from: 2016-05-13 Created: 2016-04-14 Last updated: 2017-02-20Bibliographically approved
List of papers
1. Local structures and al/si ordering in lanthanum aluminosilicate glasses explored by advanced al 27 nmr experiments and molecular dynamics simulations
Open this publication in new window or tab >>Local structures and al/si ordering in lanthanum aluminosilicate glasses explored by advanced al 27 nmr experiments and molecular dynamics simulations
Show others...
2012 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 14, no 45, 15866-15878 p.Article in journal (Refereed) Published
Abstract [en]

The structures of 15 La-Al-Si-O glasses, whose compositions span 11-28 mol% La2O3, 11-30 mol% Al2O3, and 45-78 mol% SiO2, are explored over both short and intermediate length-scales by using a combination of solid-state Al-27 magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) simulations. MAS NMR reveals Al speciations dominated by AlO4 groups, with minor but significant fractions of AlO5 (5-10%) and AlO6 (less than or similar to 3%) polyhedra present in all La2O3-Al2O3-SiO2 glasses; the amounts of Al-[5] and Al-[6] coordinations increase for decreasing molar fraction of Si. The MD simulations reproduce this compositional trend, with the fractional populations of AlOp groups (p = 4, 5, 6) according well with the experimental results. The modeled La speciations mainly involve LaO6 and LaO7 polyhedra, giving a range of average La3+ coordination numbers between 6.0 and 6.6; the latter increases slightly for decreasing Si content of the sample. Besides the expected bridging and non-bridging O species, minor contributions of oxygen triclusters (<= 9%) and free O-2(-) ions (<= 4%) are observed in all MD data. The glass structures exhibit a pronounced Al/Si disorder; the MD simulations reveal essentially random SiO4-SiO4, SiO4-AlOp and AlOp-AlOq (p, q = 4, 5, 6) associations, including significant amounts of AlO4-AlO4 contacts, regardless of the n(Al)/n(Si) molar ratio of the glass. The strong violation of Al-[4]-Al-[4] avoidance is verified by 2D Al-27 NMR experimentation that correlates double-quantum and single-quantum coherences, here applied for the first time to aluminosilicate glasses, and evidencing AlOp-AlOq connectivities dominated by AlO4-AlO4 and AlO4-AlO5 pairs. The potential bearings from distinct fictive temperatures of the experimental and modeled glass structures are discussed.

National Category
Physical Chemistry
Identifiers
urn:nbn:se:su:diva-83973 (URN)10.1039/c2cp42858j (DOI)000310460400030 ()
Note

AuthorCount:5;

Available from: 2012-12-17 Created: 2012-12-17 Last updated: 2017-12-06Bibliographically approved
2. Direct O-17 NMR experimental evidence for Al-NBO bonds in Si-rich and highly polymerized aluminosilicate glasses
Open this publication in new window or tab >>Direct O-17 NMR experimental evidence for Al-NBO bonds in Si-rich and highly polymerized aluminosilicate glasses
2015 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 17, no 28, 18269-18272 p.Article in journal (Refereed) Published
Abstract [en]

By using solid-state O-17 NMR spectroscopy, we provide the first direct experimental evidence for bonds between Al and non-bridging oxygen (NBO) ions in aluminosilicate glasses based on rare-earth (RE) elements, where RE = {Lu, Sc, Y}. The presence of similar to 10% Al-NBO moieties out of all NBO species holds regardless of the precise glass composition, at odds with the conventional structural view that Al-NBO bonds are absent in highly polymerized and Si-rich aluminosilicate glass networks.

National Category
Physical Chemistry
Research subject
Physical Chemistry
Identifiers
urn:nbn:se:su:diva-119772 (URN)10.1039/c5cp02985f (DOI)000357808500005 ()
Available from: 2015-08-24 Created: 2015-08-24 Last updated: 2017-12-04Bibliographically approved
3. The Bearings from Rare-Earth (RE=La, Lu, Sc, Y) Cations on the Oxygen Environments in Aluminosilicate Glasses: A Study by Solid-State 17O NMR, Molecular Dynamics Simulations and DFT Calculations
Open this publication in new window or tab >>The Bearings from Rare-Earth (RE=La, Lu, Sc, Y) Cations on the Oxygen Environments in Aluminosilicate Glasses: A Study by Solid-State 17O NMR, Molecular Dynamics Simulations and DFT Calculations
(English)Manuscript (preprint) (Other academic)
National Category
Physical Chemistry
Research subject
Physical Chemistry
Identifiers
urn:nbn:se:su:diva-129064 (URN)
Available from: 2016-04-13 Created: 2016-04-13 Last updated: 2016-05-06Bibliographically approved
4. Sc and Y Environments in Rare-Earth Aluminosilicate Glasses Unveiled by 45Sc and 89Y NMR Spectroscopy, MD Simulations, and DFT Calculations
Open this publication in new window or tab >>Sc and Y Environments in Rare-Earth Aluminosilicate Glasses Unveiled by 45Sc and 89Y NMR Spectroscopy, MD Simulations, and DFT Calculations
(English)Manuscript (preprint) (Other academic)
National Category
Physical Chemistry
Research subject
Physical Chemistry
Identifiers
urn:nbn:se:su:diva-129065 (URN)
Available from: 2016-04-13 Created: 2016-04-13 Last updated: 2016-04-29Bibliographically approved

Open Access in DiVA

Structure of Rare-Earth Aluminosilicate Glasses Probed by Solid-State NMR Spectroscopy and Quantum Chemical Calculations(10877 kB)236 downloads
File information
File name FULLTEXT01.pdfFile size 10877 kBChecksum SHA-512
2f091ffa5244002c1ef8fadef86fcf9a79ba206618cc83b151896ce7fb79afa5f8e415a577214a5a5fe4a94d9244ce397aa40be59dd9c34e479909134632b08d
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Jaworski, Aleksander
By organisation
Department of Materials and Environmental Chemistry (MMK)
Physical Chemistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 236 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 808 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf