Glasses on the Nanoscale

Eckert, Hellmut; Ribeiro, Sidney J. L.; Santagneli, Silvia H.; Nalin, Marcelo; Poirier, Gaël; Messaddeq, Younès

doi:10.1007/978-3-642-20595-8_18

Cited by 3 publications

(2 citation statements)

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“…Dotted curve: statistical distribution of connectivities expected at a B/Si ratio of unity 63 ECKERT | 179 containing the intermediate oxide Al 2 O 3 as summarized in various contributions 64,65 and reviews. [66][67][68] Alongside, they have been used to explore distance relations between network former and network modifier species offering insights into spatial distributions of the network modifiers and the mechanisms of local charge compensation. 52,[66][67][68][69] In particular, these methods have provided unique insights into the structural origins of network former mixing effects upon thermal and mechanical stabilities and ionic conductivities in many ion-conducting systems.…”

Section: Connectivity Distribution In Mixednetwork Glasses Studied mentioning

confidence: 99%

Spying with spins on messy materials: 60 Years of glass structure elucidation byNMRspectroscopy

Eckert

2018

Int J of Appl Glass Sci

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Glasses remain a focus of attraction to fundamental researchers and materials engineers alike. The desire of controlling physical property combinations by compositional design inspires the search for fundamental structural concepts describing the short‐ and medium‐range order of the glassy state. From its early beginnings more than 60 years ago, solid‐state nuclear magnetic resonance (NMR) spectroscopy has been making significant contributions toward this objective. Being element‐selective, inherently quantitative as well as selective to the local environment, NMR in many ways presents an ideal experimental tool of structural investigation of glasses. Over the years, substantial NMR methods development, along with advances in the theoretical interpretation of NMR parameters, have significantly enhanced our fundamental knowledge of medium‐range order and of composition‐structure‐function relationships. As we are approaching the 60th anniversary of the publication of the first article dealing with this topic (A.H. Silver and P.J. Bray, The Journal of Chemical Physics 1958, 29, 984), it is time to look back at the amazing scientific trajectory this field of investigation has taken, from the early beginnings to the present state of the art. As such, this overview does not strive to be comprehensive, but adopts a personal perspective, highlighting what in the view of the author have been influential developments and important insights obtained during the various phases of scientific inquiry in this research field.

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Section: Connectivity Distribution In Mixednetwork Glasses Studied mentioning

confidence: 99%

Spying with spins on messy materials: 60 Years of glass structure elucidation byNMRspectroscopy

Eckert

2018

Int J of Appl Glass Sci

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“…Solid-state NMR is a powerful tool for structural analysis of disordered and complex materials. 1 The technique provides insight into the local chemical environment of nuclei and is complementary to structural information provided by diffraction and other spectroscopic methods (e.g., IR and Raman). Typically, interpretation of NMR spectra of amorphous materials is done by comparison with crystalline systems.…”

Section: ■ Introductionmentioning

confidence: 99%

First-Principles Calculations and Analysis of²⁹Si Nuclear Magnetic Resonance Chemical Shifts in Silicon Oxycarbide Ceramics

Nimmo

Kroll

2014

J. Phys. Chem. C

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We calculate 29 Si NMR chemical shifts for silicon atoms in different chemical environments observed in amorphous silicon oxycarbide ceramics using a library of optimized structural models and the gauge-including projector augmented wave (GIPAW) method. For each type of mixed tetrahedral environment, {Si}O 4 , {Si}O 3 C, and {Si}O 2 C 2 , we develop linear angular correlation functions that relate the 29 Si NMR shift of the central silicon atom to the Si−O−Si angles surrounding it. The bonding nature of carbon atoms, whether 4-fold (sp 3 ) or 3-fold (sp 2 ) connected, impacts the chemical shift of {Si}O 3 C units and can be used to distinguish between Si−C bonding in the "glassy" SiCO host structure and at the interface to so-called "free" carbon. With the derived correlation functions, we analyze two representative experimental 29 Si NMR spectra and extract their angle distributions. Our results are in agreement with X-ray and neutron diffraction data. Probing for an interface between "free" carbon and "glassy" SiCO host in a C-rich SiCO material, we find no evidence of significant bonding between Si and threeconnected (sp 2 ) C. Rather, the material exhibits a large fraction of wide Si−O−Si angles, which are typical of cage-like and zeolitic structures.

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Structural and optical characterization of crystals obtained via solid state reactions in the In2O3–TiO2–Al2O3 pseudoternary system

Medrano-Pesqueira¹,

Brown²,

Möncke

et al. 2019

SN Appl. Sci.

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In this article, a synthesis of the compound In 2 O 3-TiO 2-Al 2 O 3 (molar relation 3:4:1 and 5:8:1) at 1350 °C by solid-state reactions is described. The compounds were obtained after heat treatment at 1350 °C for two days. X-ray diffraction patterns indicate that the synthesized samples belong to the monoclinic crystal system with the space group C 2/m. An agglomeration of the crystals was observed by scanning electron microscopy for the heat-treated samples of either composition (S1HT and S2HT). Atomic quantitative analysis showed variations of the two compositions presented and TEM analyses confirmed that In 3 Ti 2 AlO 10 crystals were formed. Partial nanocrystallization and irregularities can be observed in the micrographs. Both samples were polymorphic and presented chain discontinuities attributed to oxygen vacancies and/or distortions in the structure. UV-vis measurements were performed obtaining a band gap ~ 3.2 eV for all the samples analyzed. XPS analysis for S1HT and S2HT confirmed the expected oxidation of the compounds.

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Glasses on the Nanoscale

Cited by 3 publications

References 176 publications

Spying with spins on messy materials: 60 Years of glass structure elucidation byNMRspectroscopy

Spying with spins on messy materials: 60 Years of glass structure elucidation byNMRspectroscopy

First-Principles Calculations and Analysis of²⁹Si Nuclear Magnetic Resonance Chemical Shifts in Silicon Oxycarbide Ceramics

Structural and optical characterization of crystals obtained via solid state reactions in the In2O3–TiO2–Al2O3 pseudoternary system

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Glasses on the Nanoscale

Cited by 3 publications

References 176 publications

Spying with spins on messy materials: 60 Years of glass structure elucidation byNMRspectroscopy

Spying with spins on messy materials: 60 Years of glass structure elucidation byNMRspectroscopy

First-Principles Calculations and Analysis of29Si Nuclear Magnetic Resonance Chemical Shifts in Silicon Oxycarbide Ceramics

Structural and optical characterization of crystals obtained via solid state reactions in the In2O3–TiO2–Al2O3 pseudoternary system

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First-Principles Calculations and Analysis of²⁹Si Nuclear Magnetic Resonance Chemical Shifts in Silicon Oxycarbide Ceramics