title: Structural characterization of glassy phases in the system Na2O-Ga2O3-P2O5 by MAS-NMR, EXAFS and vibrational spectroscopy. I. Cations coordination.
abstract: The cationic coordinations of phosphate based gallium sodium glasses in the system Na2O-Ga2O3-P2O5 have been studied by several techniques (71Ga and 23Na MAS-NMR, EXAFS and vibrational spectroscopies) in order to study the relationship between the structure and the chemical composition. We found that three different environments are available for the gallium ions while it is very difficult to get accurate information on the sodium coordinations. Our data show that in orthophosphate glasses, gallium is mainly tetrahedral but when the mean phosphate chain length increases, its coordination becomes more and more octahedral. In these glassy structure, it becomes then possible to dissolve large amounts of typically octahedral cations like Fe3+ or Cr3+.
authors.affiliation: Département de Chimie Générale, Institut de Chimie B6, Université de Liège, Sart-Tilman, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Belkébir
authors.forename: J
authors.initials: J
authors.lastname: Rocha
authors.forename: A P
authors.initials: AP
authors.lastname: Esculcas
authors.forename: P
authors.initials: P
authors.lastname: Berthet
authors.forename: S
authors.initials: S
authors.lastname: Poisson
authors.forename: B
authors.initials: B
authors.lastname: Gilbert
authors.forename: Z
authors.initials: Z
authors.lastname: Gabelica
authors.forename: G
authors.initials: G
authors.lastname: Llabres
authors.forename: F
authors.initials: F
authors.lastname: Wijzen
authors.forename: A
authors.initials: A
authors.lastname: Rulmont
mesh_terms: D002412:Cations / Q000737:chemistry; D002857:Chromium / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D005708:Gallium / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010710:Phosphates / Q000737:chemistry; D012964:Sodium / Q000737:chemistry; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D002412:Cations; D005290:Ferric Compounds; D010710:Phosphates; D002857:Chromium; D012964:Sodium; D005708:Gallium