57Fe Mössbauer and DTA study of R2O·2FeO·V2O5·P2O5 glasses (R = Li, Na)

The 57Fe Mössbauer spectra of xLi2O·2FeO·V2O5·P2O5 and xNa2O·2FeO·V2O5·P2O5 glasses (x = 0, 0.5, 1.0 and 1.5) consist of two doublets due to FeII and FeIII. The isomer shift indicates that FeIII atoms form FeIIIO4 tetrahedra or FeIIIO6 octahedra, while FeII atoms from FeIIO6 octahedra. A liner relat...

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Bibliographic Details
Published in:Journal of the Ceramic Society of Japan 2008, Vol.116(1353), pp.637-640
Main Authors: KURIMOTO, Hiroshi, NISHIDA, Tetsuaki, OKADA, Shigeto, YAMAKI, Jun-ichi
Format: Article
Language:English
Subjects:
57Fe Mössbauer spectra
DTA curve
Maricite-type structure
Olivine-type structure
Tg-Δ Rule
Vanadate glass
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Summary:The 57Fe Mössbauer spectra of xLi2O·2FeO·V2O5·P2O5 and xNa2O·2FeO·V2O5·P2O5 glasses (x = 0, 0.5, 1.0 and 1.5) consist of two doublets due to FeII and FeIII. The isomer shift indicates that FeIII atoms form FeIIIO4 tetrahedra or FeIIIO6 octahedra, while FeII atoms from FeIIO6 octahedra. A liner relationship exists between the glass transition temperature, Tg, and the quadrupole splitting, Δ, of FeIII atoms in the Mössbauer spectra. Slopes of the straight lines were estimated to be 460 and 370°C (mm s-1)-1 in xLi2O·2FeO·V2O5·P2O5 and xNa2O·2FeO·V2O5·P2O5 glasses, respectively. These results suggest that FeIII atoms form oxygenpolyhedra that are intermediate between FeIIIO4 tetrahedra and FeIIIO6 octahedra. The electric conductivity obtained by a dc four-probe method was of the order of 10-5 to 10-6 S cm-1.
ISSN:1882-0743
1348-6535
DOI:10.2109/jcersj2.116.637