Structural characterisation of glassy phases in the system Na2O–Al2O3–P2O5 by MAS and solution NMR, EXAFS and vibrational spectroscopy

Belkébir, A.; Rocha, João; Esculcas, A.P.; Berthet, P.; Gilbert, Bernard; Gabélica, Z.; Llabrès, Gabriel; Wijzen, F.; Rulmont, A.

doi:10.1016/s1386-1425(98)00316-3

Cited by 50 publications

(45 citation statements)

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“…38 With the substitution of boron, the intensity of the peak corresponding to the AlO 5 units had decreased and the same was observed for the AlO 6 units. These changes were possibly observed because of the rearrangements of the AlPO 4 network structure.…”

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Structural elucidation of NASICON (Na₃Al₂P₃O₁₂) based glass electrolyte materials: effective influence of boron and gallium

et al. 2018

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Understanding the conductivity variations induced by compositional changes in sodium super ionic conducting (NASICON) glass materials is highly relevant for applications such as solid electrolytes for sodium (Na) ion batteries. In the research reported in this paper, NASICON-based NCAP glass (Na 2.8 Ca 0.1 Al 2 P 3 O 12 ) was selected as the parent glass. The present study demonstrates the changes in the Ga nuclei) were used. The Raman spectrum revealed that the NCAP glass structure is more analogous to the AlPO 4 mesoporous glass structure. The Ga MAS-NMR spectrum suggests that gallium cations in the NCAGP glass compete with the alumina cations and occupy four (GaO 4 ), five (GaO 5 ) and six (GaO 6 ) coordinated sites. The Raman spectrum of NCAGP glass indicates that sodium cations have also been substituted by gallium cations in the NCAP glass structure. From impedance analysis, the dc conductivity of the NCAP glass ($3.13 Â 10 À8 S cm À1) is slightly decreased with the substitution of gallium ($2.27 Â 10 À8 S cm À1) but considerably decreased with the substitution of boron ($1.46 Â 10 À8 S cm À1 ). The variation in the conductivity values are described based on the structural changes of NCAP glass with the substitution of gallium and boron.

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Structural elucidation of NASICON (Na₃Al₂P₃O₁₂) based glass electrolyte materials: effective influence of boron and gallium

et al. 2018

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“…[17][18][19][20] One such study on sodium aluminophosphates demonstrated that at low concentrations, aluminium adopts a 6-fold coordinated environment. 20 However, as the concentration of Al 2 O 3 is increased above ∼5mol.%,theaverage aluminium coordination number decreases as 4 and 5-fold environments are formed at the expense of aluminium in octahedral units.…”

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Structural study of Al2O3-Na2O-CaO-P2O5 bioactive glasses as a function of aluminium content

Smith

King

Barney

et al. 2013

The Journal of Chemical Physics

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Calcium phosphate based biomaterials are extensively used in the context of tissue engineering: small changes in composition can lead to significant changes in properties allowing their use in a wide range of applications. Samples of composition (Al 2 O 3 ) x (Na 2 O) 0.11-x (CaO) 0.445 (P 2 O 5 ) 0.445 , where x = 0, 0.03, 0.05, and 0.08, were prepared by melt quenching. The atomic-scale structure has been studied using neutron diffraction and solid state 27 Al MAS NMR, and these data have been rationalised with the determined density of the final glass product. With increasing aluminium concentration the density increases initially, but beyond about 3 mol. % Al 2 O 3 the density starts to decrease. Neutron diffraction data show a concomitant change in the aluminium speciation, which is confirmed by 27 Al MAS NMR studies. The NMR data reveal that aluminium is present in 4, 5, and 6-fold coordination and that the relative concentrations of these environments change with increasing aluminium concentration. Materials containing aluminium in 6-fold coordination tend to have higher densities than analogous materials with the aluminium found in 4-fold coordination. Thus, the density changes may readily be explained in terms of an increase in the relative concentration of 4-coordinated aluminium at the expense of 6-fold aluminium as the Al 2 O 3 content is increased beyond 3 mol. %.

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“…According to the literature [11,16], the IR spectrum of crystalline AlPO 4 in the range 1400-400 cm -1 consists of three strong bands with maxima at ~1180- ] tetrahedra were highly symmetric (close to T d ). Vibrational spectra (IR and Raman) of phosphoquartz (berlinite), phosphocristobalite, and phosphotridymite consist of bands in these same ranges [16].…”

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“…Vibrational spectra (IR and Raman) of phosphoquartz (berlinite), phosphocristobalite, and phosphotridymite consist of bands in these same ranges [16]. Narrow bands in these ranges were especially strong in the most crystallized AMB2a.…”

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IR and Raman Spectroscopy of Sodium-Aluminophosphate Glasses for Immobilizing High-Level Wastes from Spent Nuclear Fuel Reprocessing

Stefanovsky

Myasoedov

Remizov³

et al. 2014

J Appl Spectrosc

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The structure of sodium-aluminophosphate glasses containing constituents of high-level wastes (cesium, magnesium, copper, and molybdenum oxides) from uranium-graphite reactors was studied by IR and Raman spectroscopy coupled with x-ray diffraction. The structural network was shown to be composed of short P-O chains with embedded AlO 4 tetrahedra. Cross-linking by Mg 2+ was possible in the Mg-bearing samples. The effect of the other oxides (Cs 2 O, MoO 3 , CuO) on the glass structure was negligible for the occurring amounts. The glasses devitrifi ed partially upon quenching and more strongly upon annealing. This was refl ected in splitting of the vibrational bands for bonds in the glass anionic structural motif.Introduction. High-level wastes (HLW) from extraction reprocessing of spent nuclear fuel (SNF) from VVER-440 and BN-600 reactors, maritime reactors, and research reactors are vitrifi ed at PA Mayak in an EP-500 electric furnace in order to produce sodium-aluminophosphate glass [1]. Plant PT-1 for reprocessing SNF from AMB-type uranium-graphite reactors is currently under reconstruction. HLW that are unavoidably produced by extraction reprocessing should also be sent to the EP-500 vitrifi cation furnace and incorporated into the phosphate glass [2]. Preliminary research used fi ve raffi nate simulants corresponding to the fi ve AMB SNF U + 9% Mo/Mg, U + 9% Mo/Ca, U + 3% Mo /Mg, UO 2 + Cu/Mg, and UO 2 + Mg. The research found that Mo and Cu had a negative effect on the quality of the sodium-aluminophosphate glasses that are used at PA Mayak to immobilize HLW. These components can cause the glass to segregate and/or crystallize with the separation of molybdates and/or spinels. This has a negative effect on the rheological properties of the melts and the chemical and thermal resistance of the fi nal glass forms [3]. We studied [4] previously the phase composition and element distribution between phases of glasses bearing HLW components of SNF from AMB reactors (Cs, Mo, Mg, Cu) using x-ray phase analysis (XPA) and scanning electron microscopy (SEM). It was shown that the glasses crystallized partially upon quenching and to a large extent upon annealing with the separation of aluminum, sodium-aluminum and sodium-cesium-aluminum orthophosphates from a (Na, Cs) 3x-3 Al x PO 4 solid solution. The Cs content could reach 0.32 formula units, which affected substantially its quantitative distribution among the occurring phases and eventually the chemical and radiation resistance of the glasses.Herein we present results from a study of glasses for immobilizing HLW of SNF from AMB reactors using IR vibrational and Raman spectroscopy.Experimental. Sodium-aluminophosphate glass used to vitrify HLW and medium-level wastes (MLW) in the EP-500 electric furnace was selected as the base glass [5]. The three principal components of the phosphate glass acted as the components of HLW simulants from extraction reprocessing AMB SNF. The mass fractions of Na, Al, and P oxides decreased proportionally. Sodium was replaced by cesium in ...

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Structural characterisation of glassy phases in the system Na2O–Al2O3–P2O5 by MAS and solution NMR, EXAFS and vibrational spectroscopy

Cited by 50 publications

References 16 publications

Structural elucidation of NASICON (Na₃Al₂P₃O₁₂) based glass electrolyte materials: effective influence of boron and gallium

Structural elucidation of NASICON (Na₃Al₂P₃O₁₂) based glass electrolyte materials: effective influence of boron and gallium

Structural study of Al2O3-Na2O-CaO-P2O5 bioactive glasses as a function of aluminium content

IR and Raman Spectroscopy of Sodium-Aluminophosphate Glasses for Immobilizing High-Level Wastes from Spent Nuclear Fuel Reprocessing

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Structural characterisation of glassy phases in the system Na2O–Al2O3–P2O5 by MAS and solution NMR, EXAFS and vibrational spectroscopy

Cited by 50 publications

References 16 publications

Structural elucidation of NASICON (Na3Al2P3O12) based glass electrolyte materials: effective influence of boron and gallium

Structural elucidation of NASICON (Na3Al2P3O12) based glass electrolyte materials: effective influence of boron and gallium

Structural study of Al2O3-Na2O-CaO-P2O5 bioactive glasses as a function of aluminium content

IR and Raman Spectroscopy of Sodium-Aluminophosphate Glasses for Immobilizing High-Level Wastes from Spent Nuclear Fuel Reprocessing

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Structural elucidation of NASICON (Na₃Al₂P₃O₁₂) based glass electrolyte materials: effective influence of boron and gallium

Structural elucidation of NASICON (Na₃Al₂P₃O₁₂) based glass electrolyte materials: effective influence of boron and gallium