Dynamics of Oxidation of a Fe2+-Bearing Aluminosilicate (Basaltic) Melt
Rutherford backscattering spectroscopy (RBS) and microscopy demonstrate that the approximately 1400&deg;C oxidation of levitated droplets of a natural Fe2+-bearing aluminosilicate (basalt) melt occurs by chemical diffusion of Fe2+ and Ca2+ to the free surface of the droplet; internal oxidation of the melt results from the required counterflux of electron holes. Diffusion of an oxygen species is not required. Oxidation causes the droplets to go subsolidus; magnetite (Fe3O4) forms at the oxidation-solidification front with a morphology suggestive of a Liesegang-band nucleation process.
R. F. Cooper and J. B. Fanselow, Departments of Materials Science and Engineering and Geology and Geophysics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706, USA. J. K. R. Weber and D. R. Merkley, Intersonics Incorporated, 3453 Commercial Avenue, Northbrook, IL 60062, USA. D. B. Poker, Oak Ridge National Laboratory, Mail Stop 6048, Post Office Box 2008, Oak Ridge, TN 37831, USA.
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