Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Bonding and ion-ion interactions of Mn2+ ions in fluoride-phosphate and boro-silicate glasses probed by EPR and fluorescence spectroscopy
Δημιουργός/Συγγραφέας:	Moencke, Doris [EL] Καμίτσος, Ευστράτιος Ι.[EN] Kamitsos, Efstratios I. Herrmann, Andreas Ehrt, Doris Friedrich, Manfred
Εκδότης:	Elsevier BV, North-Holland
Τόπος έκδοσης:	AMSTERDAM
Ημερομηνία:	2011-07-01
Γλώσσα:	Αγγλικά
ISSN:	0022-3093
DOI:	10.1016/j.jnoncrysol.2011.02.017
Περίληψη:	Electron paramagnetic resonance (EPR) and Fluorescence spectroscopy are sensitive and selective methods for probing coordination and bonding of Mn2+ ions in glasses. Both methods provide additional information on Mn-Mn ion interactions and cluster formation. Mn2+ was found to be tetrahedrally coordinated in boro-silicate glasses of high optical basicity, and octahedrally coordinated in low alkaline boro-silicate glasses (duran-type) as in Fluoride-phosphate glasses. Broad emission bands and multicomponent Fluorescence decay curves in duran glasses indicate very strong Mn-Mn ion interactions and the presence of multiple Mn2+ sites. Site distribution is more homogenous in metaphosphate glasses, though concentration quenching is apparent at high Mn-levels. As the Mn-content increases the EPR spectra show exchange narrowing due to a decrease in the Mn-Mn distances in the duran series, but show extreme linewidth broadening due to increased cluster sizes at constant Mn-Mn distances for metaphosphate glasses. For the Fluoride-phosphate and boro-silicate systems investigated, Fluorescence lifetimes are found to decrease as the wavelength of the emission maximum increases and with increasing g-values of the sextet at g = 2. For octahedral coordination of Mn2+ ions the EPR hyperfine splitting constant decreases linearly with increasing optical basicity, as a result of an increasing covalent character of the Mn2+-ligand bond.
Όνομα εκδήλωσης:	11th International Conference on the Structure of Non-Crystalline Materials (NCM 11)
Ημ/νία έναρξης εκδήλωσης :	2010-06-28
Ημ/νία λήξης εκδήλωσης :	2010-07-02
Τόπος εκδήλωσης:	Paris, FRANCE
Τίτλος πηγής δημοσίευσης:	Journal of Non-crystalline Solids
Τόμος/Κεφάλαιο:	357
Τεύχος:	14
Σελίδες:	2542-2551
Θεματική Κατηγορία:	[EL] Επιστήμη (Γενικά)[EN] Science (General) [EL] Τεχνολογία (Γενικά)[EN] Technology (General)
Λέξεις-Κλειδιά:	Fluorescence EPR spectroscopy Fluoride-phosphate and boro-silicate glasses Glass basicity Manganese Cluster Materials Science, Ceramics Materials Science, Multidisciplinary
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© 2011 Elsevier B.V. All rights reserved.
Ηλεκτρονική διεύθυνση περιοδικού (link) :	http://www.elsevier.com/locate/jnoncrysol
Σημειώσεις:	Special Issue SI
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο