| Reference Type | Journal (article/letter/editorial) |
|---|
| Title | The diffusion of Fe2+ ions in spinels with relevance to the process of maghemitization |
|---|
| Journal | Mineralogical Magazine | ISSN | 0026-461X |
|---|
| Authors | Freer, W. | Author |
|---|
| O'Reilly, R. | Author |
| Year | 1980 (September) | Volume | 43 |
|---|
| Issue | 331 |
|---|
| Publisher | Mineralogical Society |
|---|
| Download URL | https://rruff.info/doclib/MinMag/Volume_43/43-331-889.pdf+ |
|---|
| DOI | doi:10.1180/minmag.1980.043.331.12Search in ResearchGate |
|---|
| Generate Citation Formats |
|---|
| Mindat Ref. ID | 3163 | Long-form Identifier | mindat:1:5:3163:3 |
|---|
|
| GUID | 0 |
|---|
| Full Reference | Freer, W., O'Reilly, R. (1980) The diffusion of Fe2+ ions in spinels with relevance to the process of maghemitization. Mineralogical Magazine, 43 (331) 889-899 doi:10.1180/minmag.1980.043.331.12 |
|---|
| Plain Text | Freer, W., O'Reilly, R. (1980) The diffusion of Fe2+ ions in spinels with relevance to the process of maghemitization. Mineralogical Magazine, 43 (331) 889-899 doi:10.1180/minmag.1980.043.331.12 |
|---|
| In | (1980, September) Mineralogical Magazine Vol. 43 (331) Mineralogical Society |
|---|
| Abstract/Notes | SummaryThe maghemitization process, by which magnetic minerals with spinel structure become progressively oxidized but remain single phase spinels, seems to be an important feature of submarine weathering. Whether the process takes place by the minerals acquiring oxygen from the sea-water or by the sea-water leaching out iron, the controlling process is the diffusion of Fe2+ in the spinel structure. Magnetic studies have suggested that during maghemitization the availability for oxidation of Fe2+ in the tetrahedral (A) sites of the spinel structure is much less than that in octahedral (B) sites. In this study the Fe2+-containing spinels FeAl2O4, FeCr2O4, FeGa2O4, and Fe2GeO4, in which Fe2+ is predominantly in either A or B sites were prepared, and the diffusion of Fe2+ was studied by (1) interdiffusion experiments with the Mg2+ counterparts and (2) oxidation experiments in air. Fe2GeO4 (Fe2+ in B sites) was found to be associated with a higher interdiffusion coefficient and lower activation energy than FeAl2O4 (75% Fe2+ in A sites). Oxidation/diffusion activation energies of 0.27 and 0.71 eV were assigned to Fe2+ in B and A sites respectively. The experiments thus provide support for the maghemitization model in which Fe2+ in B sites is preferentially oxidized. |
|---|
These are possibly similar items as determined by title/reference text matching only.
