Encyclopedia of Geomagnetism and Paleomagnetism

2007 Edition
| Editors: David Gubbins, Emilio Herrero-Bervera

Melting Temperature of Iron in the Core, Theory

  • David Price
Reference work entry
DOI: https://doi.org/10.1007/978-1-4020-4423-6_216

An accurate knowledge of the melting properties of Fe is particularly important, as the temperature distribution in the core is relatively uncertain and a reliable estimate of the melting temperature of Fe at the pressure of the inner‐core boundary (ICB) puts a constraint on core temperatures. However, there is much controversy over its high pressure melting behavior (e.g., see Shen and Heinz, 1998). Static compression measurements of the melting temperature (Tm) with the diamond anvil cell (DAC) have been made up to ∼200 GPa, but even at lower pressures results for Tm disagree by several hundred kelvins. Shock experiments are at present the only available method to determine melting at higher pressures, but their interpretation is not simple, and there is a scatter of at least 2000 K in the reported Tm of Fe at ICB pressures.

Since both quantum mechanics and experiments suggest that Fe melts from the hexagonal close‐packed (hcp) structured phase in the pressure range immediately above...

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Bibliography

  1. Alfè, D., Gillan, M.J., and Price, G.D., 1999. The melting curve of iron at the pressures of the Earth's core from ab initio calculations. Nature, 401: 462–464.CrossRefGoogle Scholar
  2. Alfè, D., Price, G.D., and Gillan, M.J., 2002a. Iron under Earth's core conditions: liquid‐state thermodynamics and high‐pressure melting curve from ab initio calculations. Physics Review, B65: 165118, 1–11.Google Scholar
  3. Alfè, D., Gillan, M.J., and Price, G.D., 2002b. Complementary approaches to the ab initio calculation of melting properties. Journal of Chemical Physics, 116: 6170–6177.CrossRefGoogle Scholar
  4. Anderson, O.L., 2003. The three‐dimensional phase diagram of iron. In Dehant, V., Creager, K.C., Karato, S‐I., and Zatman, S. (eds.), Earth's Core. AGU, Geodynamics Series, 31: 83–104.Google Scholar
  5. Belonosko, A.B., Ahuja, R., and Johansson, B., 2000. Quasi‐ab initio molecular dynamic study of Fe melting. Physics Review Letters, 84: 3638–3641.CrossRefGoogle Scholar
  6. Boehler, R., 1993. Temperature in the Earth's core from the melting point measurements of iron at high static pressures. Nature, 363: 534–536.CrossRefGoogle Scholar
  7. Brown, J.M., and McQueen, R.G., 1986. Phase transitions, Grüneisen parameter and elasticity for shocked iron between 77 GPa and 400 GPa. Journal of Geophysical Research, 91: 7485–7494.Google Scholar
  8. Laio, A., Bernard, S., Chiarotti, G.L., Scandolo, S., and Tosatti, E., 2000. Physics of iron at Earth's core conditions. Science, 287: 1027–1030.CrossRefGoogle Scholar
  9. Nguyen, J.H., and Holmes, N.C., 1999. Iron sound velocities in shock wave experiments. In Furnish, M.D., Chhabildas, L.C., and Hixson, R.S. (eds.) Shock Compression of Condensed Matter—1999. Melville, NY: American Institute of Physics, pp. 81–84.Google Scholar
  10. Poirier, J.P., and Shankland, T.J., 1993. Dislocation melting of iron and the temperature of the inner‐core boundary, revisited. Geophysical Journal International, 115: 147–151.CrossRefGoogle Scholar
  11. Shen, G.Y., and Heinze, D.L., 1998. High pressure melting of deep mantle and core materials. In Hemley, R.J. (ed.), Ultrahigh‐pressure Mineralogy. Reviews in Mineralogy, 37: 369–398.Google Scholar
  12. Stacey, F.D., and Irvine, R.D., 1977. Theory of melting: the thermodynamic basis of Lindemann's Law. Australian Journals of Physics, 30: 631–640.Google Scholar
  13. Stixrude, L., Wasserman, E., and Cohen, R.E., 1997. Composition and temperature of the Earth's inner core. Journal of Geophysical Research, 102: 24729–24739.CrossRefGoogle Scholar
  14. Williams, Q., Jeanloz, R., Bass, J., Svendsen, B., and Ahrens, T.J., 1987. The melting curve of iron to 250 GPa—a constraint on the temperature at Earth's center. Science, 236: 181–182.CrossRefGoogle Scholar
  15. Yoo, C.S., Holmes, N.C., Ross, M., Webb, D.J., and Pike, C., 1993. Shock temperatures and melting of iron at Earth core conditions. Physics Review Letters, 70: 3931–3934.CrossRefGoogle Scholar

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  • David Price

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