EXAFS AND NEAR EDGE SPECTROSCOPY IN GLASSES PREPARED UNDER DIFFERENT REDOX CONDITIONS
The local coordination of technetium, a multivalent transition metal, in borosilicate glasses was investigated using EXAFS spectroscopy. Different types of samples were prepared to study the effects of formation modes. All glasses prepared from heptavalent compounds of Tc did not contain Tc**7+. The spectra of glasses obtained by melting under reducing conditions are explained by a mixture of metallic Tc clusters and of Tc**4+ coordination. The sixfold octahedral environment of Tc in TcO-2 dominates the EXAFS spectra of samples melted in air and Pt crucibles. These results are shown and discussed in the framework of the structural behaviour of transition metals in glasses.
Bibliographic Reference: GLASS CONFERENCE, NASHVILLE, TENN. (USA), JULY 9-12, 1984, PUBL. IN: JOURNAL OF NON-CRYSTALLINE SOLIDS, VOL. 71 (1985), PP. 219-225
Record Number: 1989123090700 / Last updated on: 1987-01-01
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