High-resolution XANES spectra of iron in minerals and glasses: structural information from the pre-edge region
type: Distribution
access URL: https://hal.science/hal-00085620
format: HTML
issued: 2026-05-09T22:02:35.058641
modified: 2026-05-09T22:02:35.049160

test_moissonnage_selune
type: Agent

High-resolution XANES spectra of iron in minerals and glasses: structural information from the pre-edge region
type: Dataset
contact point: Organization
  fn: CCSD
keyword: infoeu-reposemanticsarticle
keyword: redox
keyword: iron
keyword: coordination
keyword: volcanic-glass
keyword: journal-articles
keyword: x-ray-spectroscopy
landing page: 0009-2541
description: High-resolution X-ray Absorption Near-Edge Structure (XANES) spectra of iron allow to take into account the effects of the coordination numbers on the quantification of redox values. Volcanic glasses show split pre-edge features, arising from a bimodal distribution between the relative contributions of ferric and ferrous iron. The chemical shift between these two oxidation states, 2 eV, has been resolved using a 400 Si monochromator. High-resolution pre-edge spectroscopy shows the distribution of ferric and ferrous iron between various coordination states. Ferrous iron is mostly fivefold-coordinated and minority fourfold-coordinated while ferric iron occurs in fourfold and sixfold-coordinated sites. The importance of 6Fe3+ in basaltic glasses may explain the formation of magnetite during glass oxidation. The increase of 4Fe3+ in the more silicic, pantelleritic glass is consistent with the peralkaline character of this glass. The increase of the proportion of tetrahedral Fe3+, accompanied by more covalent Fe3+–O bonds, is consistent with the chemical dependence of redox equilibria in magmatic systems, in which the most differentiated terms correspond to more oxidizing compositions.
issued: 2026-05-09T22:02:35.057516
language: en
modified: 2026-05-09T22:02:35.057520