The thermal equation of state of FeTiO3 ilmenite based on in situ X-ray diffraction at high pressures and temperatures
| Autor: | Yanbin Wang, M. van Kan Parker, W. van Westrenen, L. Gao, T. Sanehira, Stephan Klemme, J. de Vries, E. J. Tronche, Catherine McCammon, Jie Li, Bin Chen |
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| Přispěvatelé: | Petrology |
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | American Mineralogist, 95, 1708-1716. Mineralogical Society of America Tronche, E J, van Kan-Parker, M, de Vries, J, Wang, Y, Sanehira, T, Li, B Y, Chen, B, Gao, L, Klemme, S, McCammon, C A & van Westrenen, W 2010, ' The thermal equation of state of FeTiO3 ilmenite based on in situ X-ray diffraction at high pressures and temperatures ', American Mineralogist, vol. 95, pp. 1708-1716 . https://doi.org/10.2138/am.2010.3410 |
| ISSN: | 0003-004X |
| Popis: | We present in situ measurements of the unit-cell volume of a natural terrestrial ilmenite (Jagersfontein mine, South Africa) and a synthetic reduced ilmenite (FeTiO_3) at simultaneous high pressure and high temperature up to 16 GPa and 1273 K. Unit-cell volumes were determined using energy-dispersive synchrotron X-ray diffraction in a multi-anvil press. Mössbauer analyses show that the synthetic sample contained insignificant amounts of Fe^(3+) both before and after the experiment. Results were fit to Birch-Murnaghan thermal equations of state, which reproduce the experimental data to within 0.5 and 0.7 GPa for the synthetic and natural samples, respectively. At ambient conditions, the unit-cell volume of the natural sample [V_0 = 314.75 ± 0.23 (1 ) Å^3] is significantly smaller than that of the synthetic sample [V_0 = 319.12 ± 0.26 Å^3]. The difference can be attributed to the presence of impurities and Fe^(3+) in the natural sample. The 1 bar isothermal bulk moduli K_(T0) for the reduced ilmenite is slightly larger than for the natural ilmenite (181 ± 7 and 165 ± 6 GPa, respectively), with pressure derivatives K_0' = 3 ± 1. Our results, combined with literature data, suggest that the unit-cell volume of reduced ilmenite is significantly larger than that of oxidized ilmenite, whereas their thermoelastic parameters are similar. Our data provide more appropriate input parameters for thermo-chemical models of lunar interior evolution, in which reduced ilmenite plays a critical role. |
| Databáze: | OpenAIRE |
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