Phase Separation and Spatial Morphology in Sodium Silicate Glasses by AFM, Light Scattering and NMR

Hodroj, A.; Simon, Patrick; Florian, Pierre; Chopinet, Marie‐Hélène; Vaills, Y.

doi:10.1111/jace.12459

Cited by 16 publications

(35 citation statements)

References 29 publications

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“…When fitting the variation by I(x) = I0 (1 -n x), one obtains n = 6.6. This means that each Nd 3+ ion removes 6.6 31 P nuclei from the NMR signal, which is nearly equal to the number ( 7) of the superexchange coupled second neighbors.…”

Section: P Nmr Spectroscopymentioning

confidence: 99%

“…LaPO4 crystallizes either in the rhabdophane structure, which contains water molecules and corresponds to the low temperature phase, or in the monazite structure, which is the high temperature phase. As H2O molecules act as strong relaxation agents, we considered only the monazite phase, more appropriate for the study of the relaxation of 31 P by the doping ions. Two doping ions, Nd 3+ (J = 9/2, L = 6, S = 3/2) and Gd 3+ (L = 0, J = S = 7/2) were introduced in the LaPO4 matrix in order to show the influence of the electronic properties of the doping ions on the 31 P nuclear relaxation time.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

NMR and ESR relaxation in Nd- and Gd-doped LaPO₄: towards the accurate determination of the doping concentration

Maron

Dantelle

Gacoin

et al. 2014

Phys. Chem. Chem. Phys.

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We present an original method based on the (31)P solid-state NMR relaxation to determine low concentrations (<1 at%) of paramagnetic ions in monazite LaPO4 crystals with a high accuracy (∼0.1 at%). NMR experiments under static and MAS (15 kHz) conditions show that the (31)P relaxation time T1 is strongly affected by the presence of paramagnetic ions in the vicinity of the phosphorus nuclei. A linear variation of 1/T1 as a function of Nd(3+) or Gd(3+) concentration is shown in the 0-10 at% range for a homogeneous distribution of the doping ions in the matrix, which is the case when doped LaPO4 is synthesized by a soft chemistry route, i.e. by aqueous co-precipitation followed by thermal annealing. As a proof of concept for the use of this tool to study dopant homogeneity, we show that in the case of a solid-state synthesis at 1350 °C, relaxation measurements show that the homogeneous distribution of the doping ions is ensured when the mixing of the oxide precursors is performed mechanically, but not in the case of manual grinding. The electronic relaxation times of Gd(3+) and Nd(3+) ions are evaluated by ESR measurements under saturation conditions. This allows us to provide a semi-quantitative interpretation of the nuclear (31)P relaxation measurements both in Nd and Gd doped LaPO4. In addition, the comparison between nuclear and electronic relaxation suggests that Nd-Gd codoping may improve the efficiency of the Gd(3+) ion as a relaxing agent in MRI (magnetic resonance imaging) techniques.

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Section: P Nmr Spectroscopymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

NMR and ESR relaxation in Nd- and Gd-doped LaPO₄: towards the accurate determination of the doping concentration

Maron

Dantelle

Gacoin

et al. 2014

Phys. Chem. Chem. Phys.

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“…Such methods typically make fewer assumptions concerning the shape of partial spectral components, and hence require a smaller number of adjustable parameters than Gaussian-based methods. For example, principal component analysis [35] decomposes a signal into orthogonal components and is one of the most pop-ular methods [36], followed by independent component analysis [37] for statistically-independent signals. Nonnegative matrix factorization (NMF) [38] has recently gained attention since it enables a spectroscopic interpretation of the non-negative extracted features.…”

Section: Introductionmentioning

confidence: 99%

Analysis of soda-lime glasses using non-negative matrix factor deconvolution of Raman spectra

Woelffel

Claireaux

Toplis

et al. 2015

Journal of Non-Crystalline Solids

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Novel statistical analysis and machine learning algorithms are proposed for the deconvolution and interpretation of Raman spectra of silicate glasses in the Na 2 O-CaO-SiO 2 system. Raman spectra are acquired along diffusion profiles of three pairs of glasses centered around an average composition of 69.9 wt.% SiO 2 , 12.7 wt.% CaO, 16.8 wt.% Na 2 O. The shape changes of the Raman spectra across the compositional domain are analyzed using a combination of principal component analysis (PCA) and sparse non-negative matrix factorization (NMF). This procedure yields components accounting for the observed changes, as well as their mixing proportions, without any direct prior assumption as to their actual shape, number or position. These methods are applied separately to the Q band (wavenumbers in the range 850-1400 cm −1), the main band (200-850 cm −1) and to the whole spectra (200-1400 cm −1). Compositional profiles obtained by Electron Probe Micro-Analysis (EPMA) are then used to relate spectral components to structural entities. Spectral components extracted from a Q band analysis and a complete spectral analysis show significant similarities both in terms of shape of the components and their mixing proportions. This result implies a link between Q n species and the shift of the medium-range network features in the main band of the Raman spectra. To illustrate the possibilities of the method, a linear regression model is used to relate the proportions of spectral components derived from the Raman spectra to chemical composition. This model can be used to determine the composition of different glasses inside the investigated compositional domain with reasonable accuracy.

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“…The minimal spatial resolution of the method can achieve about 200 nm when using a confocal Raman microscope with a UV-laser excitation source [98]; even higher resolution (~50 nm) can be obtained using a nano-Raman implementation of the method [99]. This allows one to image sub-micron crystalline [99,100] and amorphous particles [101,102] in the PCGs. Raman scattering can be also applied to characterize the phase-separated glasses, where sizes of the structures can be well below 100 nm.…”

Section: Characterization Of Pcgsmentioning

confidence: 99%

Nano-Structured Optical Fibers Made of Glass-Ceramics, and Phase Separated and Metallic Particle-Containing Glasses

Veber

Vermillac

et al. 2019

Fibers

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For years, scientists have been looking for different techniques to make glasses perfect: fully amorphous and ideally homogeneous. Meanwhile, recent advances in the development of particle-containing glasses (PCG), defined in this paper as glass-ceramics, glasses doped with metallic nanoparticles, and phase-separated glasses show that these "imperfect" glasses can result in better optical materials if particles of desired chemistry, size, and shape are present in the glass. It has been shown that PCGs can be used for the fabrication of nanostructured fibers-a novel class of media for fiber optics. These unique optical fibers are able to outperform their traditional glass counterparts in terms of available emission spectral range, quantum efficiency, non-linear properties, fabricated sensors sensitivity, and other parameters. Being rather special, nanostructured fibers require new, unconventional solutions on the materials used, fabrication, and characterization techniques, limiting the use of these novel materials. This work overviews practical aspects and progress in the fabrication and characterization methods of the particle-containing glasses with particular attention to nanostructured fibers made of these materials. A review of the recent achievements shows that current technologies allow producing high-optical quality PCG-fibers of different types, and the unique optical properties of these nanostructured fibers make them prospective for applications in lasers, optical communications, medicine, lighting, and other areas of science and industry.Made of glass, optical fibers inherited all positive and negative properties of this material. Glasses are easy and inexpensive to produce on any scale and in any shape, they can possess high chemical stability and mechanical strength, and have high transparency. However, they could hardly compete, for example, with crystalline materials in thermal conductivity, or rare-earth elements' absorption, emission cross-sections, and available transparency range. Recent advances in glass science showed that properties of this material can be significantly improved if some additional phases are formed or impregnated in the glass. In particular, advances have been achieved in the development of particle-containing glasses: glass-ceramic materials, glasses doped with metallic nanoparticles, and phase-separated glasses. To date, these particle-containing glasses have become quite common and actively used in case of the bulk materials, but are still rather new for fiber optics.The purpose of this review is to summarize recent advances in the fabrication of structured fibers made of particle-containing glasses, their potential benefits, their actual properties, and their potential applications. The review covers three types of particle-containing glasses (PCG): crystalline dielectric particles, i.e., glass-ceramics; metallic nanoparticles (MeNPs); and dielectric amorphous particles, i.e., phase-separated glasses.First, we consider properties of the PCG bulk materials, their potenti...

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Phase Separation and Spatial Morphology in Sodium Silicate Glasses by AFM, Light Scattering and NMR

Cited by 16 publications

References 29 publications

NMR and ESR relaxation in Nd- and Gd-doped LaPO₄: towards the accurate determination of the doping concentration

NMR and ESR relaxation in Nd- and Gd-doped LaPO₄: towards the accurate determination of the doping concentration

Analysis of soda-lime glasses using non-negative matrix factor deconvolution of Raman spectra

Nano-Structured Optical Fibers Made of Glass-Ceramics, and Phase Separated and Metallic Particle-Containing Glasses

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Phase Separation and Spatial Morphology in Sodium Silicate Glasses by AFM, Light Scattering and NMR

Cited by 16 publications

References 29 publications

NMR and ESR relaxation in Nd- and Gd-doped LaPO4: towards the accurate determination of the doping concentration

NMR and ESR relaxation in Nd- and Gd-doped LaPO4: towards the accurate determination of the doping concentration

Analysis of soda-lime glasses using non-negative matrix factor deconvolution of Raman spectra

Nano-Structured Optical Fibers Made of Glass-Ceramics, and Phase Separated and Metallic Particle-Containing Glasses

Contact Info

Product

Resources

About

NMR and ESR relaxation in Nd- and Gd-doped LaPO₄: towards the accurate determination of the doping concentration

NMR and ESR relaxation in Nd- and Gd-doped LaPO₄: towards the accurate determination of the doping concentration