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Role of Iron in Calcium Phosphate Glasses
Author(s) -
BISHAY A. M.,
MAKAR L.
Publication year - 1969
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/j.1151-2916.1969.tb15849.x
Subject(s) - electron paramagnetic resonance , analytical chemistry (journal) , phosphate , absorption (acoustics) , absorption spectroscopy , activation energy , nuclear chemistry , irradiation , chemistry , electrical resistivity and conductivity , iron phosphate , materials science , crystallography , nuclear magnetic resonance , physics , organic chemistry , chromatography , quantum mechanics , nuclear physics , electrical engineering , composite material , engineering
Some physical properties okf phosphate glasses con‐taining up to about 26 mol% Fe 2 O 2 were studied. Pronounced changes in properties were observed at compositions containingabout 6, 10, and 13 mol% Fe 2 O 3 . The X‐ray diffraction spectra of devitrified (heat‐treated) samples showed new compounds near these compositions. Electron spin resonance and optical studies confirmed the presence of Fe 3+ and Fe 2+ in both 4‐ and 6‐coordination. An increase in total iron in these samples was associated with a decrease in the ratios Fe 2+ 4‐coordinated/Fe 3+ 6‐coordinated 6‐coordinated and Fe 3+ 4‐coordinated/Fe 3+ 6‐coordinated up to about 2.0 mol% Fe 2 O 3 , as shown by the intensity of the optical absorption bands at about 2.0 and 1.0 μm and by the intensity of the ESR lines at g⋍4.2 and 2.0, respectively. Samples containing up to 4.3 mol% Fe 2 O 3 showed an increase in Fe 3+ concentration and a decrease in Fe 2+ concentration after gamma irradiation. The electrical conductivity and activation energy decreased sharply with increasing Fe 2 O 3 content.