Ratios of the peak areas on Mössbauer spectra of mixtures of vivianite and amorphous ferric phosphate vary linearly with the ratios of the proportions of the phases. This makes it possible to use Mössbauer spectrometry for simple quantitative analysis of ferrous-ferric phosphates. The results of the Mössbauer analysis agree to within 3% with conventional chemical methods. Interpretation of the Mössbauer spectra of iron phosphate mixtures and oxidized vivianite is consistent with magnetic susceptibility measurements. Consideration of the spectra of a number of ferrous and ferric phosphates and oxides indicates that the Mössbauer analysis may be also applied to some phosphate-oxide mixtures. The slope of the curve of absorption intensities ratio versus proportions ratio deviates from the slope predictable by the theory. Hence, for a reasonably accurate estimation of the Fe+3 Fe+2 ratios in mixtures of minerals, calibration curves may need be constructed for each particular case.
ASJC Scopus subject areas
- Geochemistry and Petrology
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science