Titre :

Crystallization of sodium molybdate-phosphate and tungstate-phosphate glasses

Auteur(s) :

Koudelka, Ladislav [Auteur]
Kupetska, Oksana [Auteur]
Kalenda, Petr [Auteur]
Mošner, Petr [Auteur]
Montagne, Lionel [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Revel, Bertrand [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]

Titre de la revue :

Journal of Non-Crystalline Solids

Numéro :

500

Pagination :

42-48

Éditeur :

Elsevier BV

Date de publication :

2018-11-15

ISSN :

0022-3093

Mot(s)-clé(s) en anglais :

Phosphate glasses
Crystallization
Raman spectra
NMR spectra
Tungsten oxide
Molybdenum oxide

Discipline(s) HAL :

Chimie/Chimie inorganique

Résumé en anglais : [en]

Study of the glass to crystal transformation was realized for two glasses with composition 25Na2O.50MoO3.25P2O5 and 25Na2O.50MoO3.25P2O5. During the heat treatment process, 2 crystalline compounds are formed, NaMoO2PO4 and ...
Lire la suite >Study of the glass to crystal transformation was realized for two glasses with composition 25Na2O.50MoO3.25P2O5 and 25Na2O.50MoO3.25P2O5. During the heat treatment process, 2 crystalline compounds are formed, NaMoO2PO4 and NaWO2PO4, respectively. Physico-chemical properties of the corresponding glasses and crystals were compared, as well as their Raman and 31P MAS NMR spectra. DTA studies revealed crystallization peaks at 483°C in the Mo-containing glass and at 624°C in the W-containing glass; melting points of crystalline compounds were determined as 695 ±2°C for NaMoO2PO4 and 875±2°C for NaMoO2PO4. Sodium tungstate-phosphate glass has lower solubility in comparison with the sodium molybdate-phosphate glass. The study of crystallization mechanism showed a prevailing surface nucleation. 31P MAS NMR spectra of the 2 glasses showed the same shape and almost same width, which reflects a similar local environment for P in these glasses. The position of the resonance for W-containing glass at a more negative chemical shift than the Mo-containing one is attributed to the larger electrical field strength of W atoms than Mo atoms. 31P MAS NMR spectra of crystals revealed two resonances at +17 and -0.5 ppm for the Mo glass and at -0.1 and -1.9 ppm for the W glass, reflecting the presence of two different phosphorus short range environments, in agreement with their crystal structure. Raman spectra showed similarity in structural features for Mo and W glasses and isomorphic compounds. Splitting of the dominant Raman bands in the crystal spectra reflects a distortion of MoO6 and WO6 octahedra. Raman spectra also suggested the breaking of Mo-O-Mo and W-O-W linkages during crystallization.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Autre(s) projet(s) ou source(s) de financement :

project No. 18-01976S of the Grant Agency of the Czech Republic
Chevreul Institute (FR 2638)
Ministère de l’Enseignement Supérieur et de la Recherche
Région Nord Pas-de-Calais
Fonds Européen de Développement des Régions

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Équipe(s) de recherche :

RMN et matériaux inorganiques (RM2I)

Date de dépôt :

2019-05-09T09:34:05Z
2019-10-24T14:14:33Z
2022-03-08T10:12:15Z
2023-11-28T16:47:56Z
2023-12-01T09:29:37Z