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Structural features of iron‐phosphate glass
Author(s) -
Reis Signo T.,
Pontuschka Walter M.,
MogušMilanković Andrea,
Partiti Carmen S. M.
Publication year - 2017
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.14731
Subject(s) - phosphate glass , borosilicate glass , ion , dissolution , octahedron , aqueous solution , iron phosphate , mössbauer spectroscopy , materials science , phosphate , differential thermal analysis , electron paramagnetic resonance , crystallography , analytical chemistry (journal) , octahedral symmetry , chemistry , diffraction , nuclear magnetic resonance , metallurgy , physics , organic chemistry , chromatography , optics
This paper reports a study and discusses the role of Fe ions in the inhibition of corrosion of iron phosphate glasses. The structure of the 40Fe 2 O 3 –60P 2 O 5 (mol%) glass, having a confirmed dissolution rate in aqueous solution at 90°C superior to borosilicate glasses, was investigated. Samples were crystallized at characteristic temperatures defined by differential thermal analysis and analyzed by X‐ray diffraction. Crystalline phases of Fe 2 Fe[P 2 O 7 ] 2 and Fe 4 [P 2 O 7 ] 3 were detected. The hyperfine parameters from the Mössbauer spectrum indicate that both Fe 2+ and Fe 3+ ions are in octahedral coordination, and 18% of the Fe 3+ ions in the starting batch are reduced to Fe 2+ ions after melting. The broad and symmetric spectra centered in g≈2.0 from the EPR measurements indicate the presence of two or more Fe interacting ions occupying sites of relatively high local symmetry.