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Local order of V5+Ions in borate glasses investigated by EXAFS

  • Glasses in the systems Li2O–B2O3–V2O5 and ZnO–B2O3–V2O5 as well as crystalline reference substances were investigated by V-K-EXAFS. The glasses have a high modifier content ([Li2O, ZnO]/[B2O3] ratio>1) and contain 10–50 mol% V2O5. The V–O interatomic distance, coordination number and Debye–Waller factor were determined from the analysis of the measured absorption spectra. In the glasses investigated (and in binary lithium or zinc vanadate glasses too) VO4 tetrahedra are the predominant coordination polyhedra for the vanadium ions. The symmetry of the tetrahedra is more or less distorted in comparison to crystalline substances. The VO4 tetrahedra can be either directly connected to each other or incorporated into borate BO3/BO4 groupings. Structural elements which are comparable to those in crystalline substances can be discussed. In glasses of the metaborate composition, vanadium can be incorporated in chain or ring [BØ2O-]n metaborate groupings. With increasing V2O5 content theGlasses in the systems Li2O–B2O3–V2O5 and ZnO–B2O3–V2O5 as well as crystalline reference substances were investigated by V-K-EXAFS. The glasses have a high modifier content ([Li2O, ZnO]/[B2O3] ratio>1) and contain 10–50 mol% V2O5. The V–O interatomic distance, coordination number and Debye–Waller factor were determined from the analysis of the measured absorption spectra. In the glasses investigated (and in binary lithium or zinc vanadate glasses too) VO4 tetrahedra are the predominant coordination polyhedra for the vanadium ions. The symmetry of the tetrahedra is more or less distorted in comparison to crystalline substances. The VO4 tetrahedra can be either directly connected to each other or incorporated into borate BO3/BO4 groupings. Structural elements which are comparable to those in crystalline substances can be discussed. In glasses of the metaborate composition, vanadium can be incorporated in chain or ring [BØ2O-]n metaborate groupings. With increasing V2O5 content the vanadium ions can extensively replace boron ions and form distorted tetrahedra in VØ2O2- metavanadate groups. In glasses of high modifier content and low vanadium amount the vanadium ions create nearly regular tetrahedra of isolated VO43- ortho- or V2ØO64- pyrovanadate groups in the presence of B2ØO44- pyroborate, BO33- orthoborate and BØ4- groups.zeige mehrzeige weniger

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Metadaten
Autor*innen:Thomas Hübert, Günter Mosel, Marianne NofzORCiD
Dokumenttyp:Zeitschriftenartikel
Veröffentlichungsform:Verlagsliteratur
Sprache:Deutsch
Titel des übergeordneten Werkes (Deutsch):Physics and chemistry of glasses
Jahr der Erstveröffentlichung:2000
Herausgeber (Institution):Society of Glass Technology
Verlag:Thornton
Verlagsort:Sheffield
Jahrgang/Band:41
Ausgabe/Heft:5
Erste Seite:300
Letzte Seite:303
Veranstaltung:Third International Conference on borate Glasses, Crystals and Melts
Veranstaltungsort:Sofia, Bulgaria
Beginndatum der Veranstaltung:1999-07-04
Enddatum der Veranstaltung:1999-07-09
URL:http://www.ingentaconnect.com/content/sgt/pcg/2000/00000041/00000005/4105300
ISSN:0031-9090
Verfügbarkeit des Dokuments:Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
Bibliotheksstandort:Sonderstandort: Publica-Schrank
Datum der Freischaltung:19.02.2016
Referierte Publikation:Nein
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