Mössbauer spectroscopy of tektites

Aramu, F.; Brovetto, P.; Maxia, V.; Salis, M.; Spano, G.

doi:10.1007/bf02451660

Cited by 3 publications

(4 citation statements)

References 6 publications

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Section: Discussionmentioning

confidence: 99%

“…Asymmetric peak shapes, characteristic of silicate glasses, require correlated distributions to fit the spectra and cannot be quantitatively compared to studies that do not use correlated distributions [Rossano et al, 1999]. Thus, we do not include the results of those studies [e.g., Aramu et al, 1994;Costa et al, 2014;Gu et al, 2012]. Although Dunlap et al [1998] use correlated distributions, they do not report the compositions of the natural tektites in their study; thus, their results are not included in our compositional analysis.…”

Section: Trends With Compositionmentioning

confidence: 99%

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Electronic environments of ferrous iron in rhyolitic and basaltic glasses at high pressure

et al. 2017

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The physical properties of silicate melts within Earth's mantle affect the chemical and thermal evolution of its interior. Chemistry and coordination environments affect such properties. We have measured the hyperfine parameters of iron‐bearing rhyolitic and basaltic glasses up to ~120 GPa and ~100 GPa, respectively, in a neon pressure medium using time domain synchrotron Mössbauer spectroscopy. The spectra for rhyolitic and basaltic glasses are well explained by three high‐spin Fe2+‐like sites with distinct quadrupole splittings. Absence of detectable ferric iron was confirmed with optical absorption spectroscopy. The sites with relatively high and intermediate quadrupole splittings are likely a result of fivefold and sixfold coordination environments of ferrous iron that transition to higher coordination with increasing pressure. The ferrous site with a relatively low quadrupole splitting and isomer shift at low pressures may be related to a fourfold or a second fivefold ferrous iron site, which transitions to higher coordination in basaltic glass, but likely remains in low coordination in rhyolitic glass. These results indicate that iron experiences changes in its coordination environment with increasing pressure without undergoing a high‐spin to low‐spin transition. We compare our results to the hyperfine parameters of silicate glasses of different compositions. With the assumption that coordination environments in silicate glasses may serve as a good indicator for those in a melt, this study suggests that ferrous iron in chemically complex silicate melts likely exists in a high‐spin state throughout most of Earth's mantle.

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Section: Discussionmentioning

confidence: 99%

Section: Trends With Compositionmentioning

confidence: 99%

Electronic environments of ferrous iron in rhyolitic and basaltic glasses at high pressure

et al. 2017

View full text Add to dashboard Cite

show abstract

“…One important characteristics of a natural glass is cation coordination number [2], as this is affected by the pressure and temperature conditions present at the time of solidification and is indicative of the conditions under which glass formation process took place. Iron has been shown to be a useful probe of structure in natural glasses and has been investigated using Mö ssbauer effect spectroscopy [3][4][5][6][7][8][9][10][11]. In general, the results of Mö ssbauer effect spectroscopy for the analysis of Fe oxidation state ratios in glasses depend critically on the method of spectral analysis.…”

Section: Introductionmentioning

confidence: 99%

“…As well, it has been shown that the Mössbauer technique is not only sensitive to the different Fe oxidation states, but may also be able to distinguish between octahedrally and tetrahedrally coordinated ferrous iron, Fe 2þ oct and Fe 2þ tet , respectively. While there has been consistent progress in the interpretation and understanding of the Mössbauer effect spectra of tektites over the years [3][4][5][6][7][8][9][10][11], there has been relatively little (and virtually no recent) Mö ssbauer work on other impact related materials [3,4]. In the present work we have used Mö ssbauer effect spectroscopy to study Fe site properties in a number of well-known impact glasses and have considered these spectra in the context of analysis techniques that have been recently applied to tektite spectra [11].…”

Section: Introductionmentioning

confidence: 99%