@article{WilkeSchmidtFargesetal.2006,
  author    = {Wilke, Max and Schmidt, Christian and Farges, Francois and Malavergne, Valerie and Gautron, Laurent and Simionovici, Alexandre and Hahn, Matthias and Petit, Pierre-Emanuel},
  title     = {Structural environment of iron in hydrous aluminosilicate glass and melt-evidence from X-ray absorption spectroscopy},
  doi       = {10.1016/j.chemgeo.2006.01.017},
  year      = {2006},
  abstract  = {The iron speciation in hydrous haplotonalitic and haplogranitic silicate glasses was studied using XAFS spectroscopy and transmission electron microscopy (TEM). Spectral features occurring at the main crest of the XANES at the iron K-edge of hydrous glasses indicate contributions to the spectra by iron-moieties present in a more ordered structural environment than found in the dry glass. These differences are also suggested by analysis of the EXAFS. These effects are not completely suppressed even for those samples that were quenched with a higher cooling rate. Strongest differences to the dry glass are observed for a sample that was quenched slowly through the temperature of glass transformation. Crystals (60 to 1500 nm in size) of magnetite, maghemite and another unidentified phase were observed in this sample by TEM, whereas no crystals were found in samples quenched with regular or high cooling rates. In-situ XANES measurements up to 700 degrees C and 500 MPa were performed to reveal the origin (i.e., during synthesis or quench) of the structural differences for those hydrous glasses that do not display any detectable crystallization. The comparison of XANES spectra collected on Fe2+ in water-saturated haplogranitic melt at 700 degrees C and 500 MPa and on Fe2+ in dry melt at 1150 degrees C shows that the local structural environment of Fe2+ in both systems is similar. This indicates that there is no detectable and direct influence of water on the local structure around iron in this type of melt. Hence, the differences observed between hydrous and dry glasses can only be related to artefacts formed during the quench process. (c) 2006 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{WilkePartzschWelteretal.2007,
  author    = {Wilke, Max and Partzsch, G. M. and Welter, E. and Farges, Francois},
  title     = {Redox Reaction In Silicate Melts Monitored By Static In-Situ Fe K-edge XANES Up To 1180 C},
  year      = {2007},
  language  = {en}
}
@article{WilkePartzschSchmidtetal.2004,
  author    = {Wilke, Max and Partzsch, G. M. and Schmidt, C. and Farges, Francois},
  title     = {In-situ study of the iron species in silicate melts},
  issn      = {0016-7037},
  year      = {2004},
  language  = {en}
}
@article{WilkePartzschFarges2004,
  author    = {Wilke, Max and Partzsch, G. M. and Farges, Francois},
  title     = {XAFS of iron in silicate melt at high temperature},
  issn      = {0024-4937},
  year      = {2004},
  language  = {en}
}
@article{WilkePartzschBernhardtetal.2004,
  author    = {Wilke, Max and Partzsch, G. M. and Bernhardt, Rita and Lattard, D.},
  title     = {Determination of the iron oxidation state in basaltic glasses using XANES at the K-edge},
  issn      = {0009-2541},
  year      = {2004},
  abstract  = {Fe K-edge X-ray absorption near edge structure (XANES) and Mossbauer spectra were collected on synthetic glasses of basaltic composition and of glasses on the sodium oxide-silica binary to establish a relation between the pre- edge of the XANES at the K-edge and the Fe oxidation state of depolymerised glasses. Charges of sample material were equilibrated at ambient pressure, superliquidus temperatures and oxygen fugacities that were varied over a range of about 15 orders of magnitude. Most experiments were carried out in gas-flow furnaces, either with pure oxygen, air, or different CO/CO2 mixtures. For the most reduced conditions, the samples charges were enclosed together with a pellet of the IQF oxygen buffer in an evacuated silica glass ampoule. Fe3+/SigmaFe x 100 of the samples determined by Mossbauer spectroscopy range between 0\% and 100\%. Position and intensity of the pre-edge centroid position vary strongly depending on the Fe oxidation state. The pre-edge centroid position and the Fe oxidation state determined by Mossbauer spectroscopy are nonlinearly related and have been fitted by a quadratic polynomial. Alternatively, the ratio of intensities measured at positions sensitive to Fe2+ and Fe3+, respectively, provides an even more sensitive method. Pre- edge intensities of the sample suite indicate average Fe co-ordination between 4 and 6 for all samples regardless of oxidation state. A potential application of the calibration given here opens the possibility of determining Fe oxidation state in glasses of similar compositions with high spatial resolution by use of a Micro-XANES setup (e.g., glass inclusions in natural minerals). (C) 2004 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{WilkePartzschBernhardtetal.2005,
  author    = {Wilke, Max and Partzsch, G. M. and Bernhardt, Rita and Lattar, D.},
  title     = {Determination of the iron oxidation state in basaltic glasses using XANES at the K-edge},
  issn      = {0009-2541},
  year      = {2005},
  abstract  = {Fe K-edge X-ray absorption near edge structure (XANES) and Mossbauer spectra were collected on synthetic glasses of basaltic composition and of glasses on the sodium oxide-silica binary to establish a relation between the pre- edge of the XANES at the K-edge and the Fe oxidation state of depolymerised glasses. Charges of sample material were equilibrated at ambient pressure, superliquidus temperatures and oxygen fugacities that were varied over a range of about 15 orders of magnitude. Most experiments were carried out in gas-flow furnaces, either with pure oxygen, air, or different CO/CO2 mixtures. For the most reduced conditions, the samples charges were enclosed together with a pellet of the IQF oxygen buffer in an evacuated silica glass ampoule. Fe3+/Sigma Fe x 100 of the samples determined by Mossbauer spectroscopy range between 0\% and 100\%. Position and intensity of the pre-edge centroid position vary strongly depending on the Fe oxidation state. The pre-edge centroid position and the Fe oxidation state determined by Mossbauer spectroscopy are nonlinearly related and have been fitted by a quadratic polynomial. Alternatively, the ratio of intensities measured at positions sensitive to Fe2+ and Fe3+, respectively, provides an even more sensitive method. Pre- edge intensities of the sample suite indicate average Fe co-ordination between 4 and 6 for all samples regardless of oxidation state. A potential application of the calibration given here opens the possibility of determining Fe oxidation state in glasses of similar compositions with high spatial resolution by use of a Micro-XANES setup (e.g., glass inclusions in natural minerals). (c) 2004 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{WilkeNabelekGlascock2002,
  author    = {Wilke, Max and Nabelek, Peter I. and Glascock, Michael D.},
  title     = {B and Li in Proterozoic metapelites from the Black Hills, U.S.A. : Implications for the origin of leucogranitic magmas},
  year      = {2002},
  language  = {en}
}
@article{WilkeFargesPetitetal.2001,
  author    = {Wilke, Max and Farges, Francois and Petit, Pierre-Emanuel and Brown Jr., Gordon E. and Martin, Francois},
  title     = {Oxidation state and coordination of Fe in minerals : an Fe K XANES spectroscopic study},
  year      = {2001},
  language  = {en}
}
@article{WilkeFargesPartzschetal.2007,
  author    = {Wilke, Max and Farges, Francois and Partzsch, G. M. and Schmidt, C. and Behrens, Harald},
  title     = {Speciation of Fe in silicate glasses and melts by in-situ XANES spectroscopy},
  year      = {2007},
  language  = {en}
}
@article{WilkeBehrensBurkhardetal.2002,
  author    = {Wilke, Max and Behrens, Harald and Burkhard, Dorothee J. M. and Rossano, Stephanie},
  title     = {The oxidation state of iron in silicic melt at 500 MPa water pressure},
  year      = {2002},
  language  = {en}
}