Encyclopedia of Geomagnetism and Paleomagnetism

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

Melting Temperature of Iron in the Core, Experimental

  • Guoyin Shen
Reference work entry
DOI: https://doi.org/10.1007/978-1-4020-4423-6_215


There are two major techniques commonly used for ultrahigh pressure melting studies: shock wave experiments and the internally heated diamond anvil cell (DAC). In shock compression experiments, the sample is subjected to high pressures and high temperatures by dynamic processes (see  Shock wave experiments). In DAC experiments, pressure is generated by pressing two opposing diamond anvils, while heating is applied resistively and/or using laser heating. Both techniques have been extensively applied to study high pressure melting of iron. However, accurate determination of melting is exceedingly difficult at extremely high pressure and temperature conditions. The associated weaknesses—the short timescale in shock compression and the small sample size in DAC—are reflected by the large uncertainties and the discrepancy among literature values on melting temperature of iron in the core.

In this section, we begin with a brief description of the generation of simultaneous high...

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  1. Ahrens, T.J., Holland, K.G., and Chen, G.Q., 2002. Phase diagram of iron, revised‐core temperatures. Geophysical Research Letters, 29: doi:10.1029/2001GL014350.Google Scholar
  2. Andrault, D., Fiquet, G., Kunz, M., Visocekas, F., and Hausermann, D., 1997. The orthorhombic structure of iron: an in situ study at high‐temperature and high‐pressure. Science, 278: 831–834.CrossRefGoogle Scholar
  3. Birch, F., 1952. Elasticity and composition of Earth's interior. Journal of Geophysical Research, 57: 227–286.Google Scholar
  4. Boehler, R., 1986. The phase diagram of iron to 430 kbar. Geophysical Research Letters, 13: 1153–1156.Google Scholar
  5. Boehler, R., 1992. Melting of Fe‐FeO and Fe‐FeS systems at high pressures: constraints on core temperatures. Earth and Planetaty Science Letters, 111: 217–227.CrossRefGoogle Scholar
  6. Boehler, R., 1993. Temperatures in the Earth's core from melting‐point measurements of iron at high static pressures. Nature, 363: 534–536.CrossRefGoogle Scholar
  7. Boehler, R., 1996. Melting of mantle and core materials at very high pressures. Philosophical Transactions of the Royal Society of London, Series A, 354: 1265–1278.CrossRefGoogle Scholar
  8. Boehler, R., 2000. High pressure experiments and the phase diagram of lower mantle and core materials. Reviews of Geophysics, 38: 221–245.CrossRefGoogle Scholar
  9. 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
  10. de Vos, J.C., 1954. A new determination of the emissivity of tungsten ribbon. Physica, 20: 690–714.CrossRefGoogle Scholar
  11. Dubrovinsky, L.S., Saxena, S.K., and Lazor, P., 1998. Stability of β‐phase: a new synchrotron x‐ray study of heated iron at high pressure. European Journal of Mineralogy, 10: 43–47.Google Scholar
  12. Fei, Y., Bertka, C.M., and Finger, L.W., 1997. High pressure iron sulfur compound, Fe3O2, and melting relations in the Fe‐FeS system. Science, 275: 1621–1623.CrossRefGoogle Scholar
  13. Jeanloz, R., and Kavner, A., 1996. Melting criteria and imaging spectroradiometry in laser‐heated diamond‐cell experiments. Philosophical Transactions of the Royal Society of London, Series A, 354: 1279–1305.CrossRefGoogle Scholar
  14. Jephcoat, A.P., and Besedin, S.P., 1996. Temperature measurement and melting determination in the laser‐heated diamond‐anvil cell. Philosophical Transactions of the Royal Society of London, Series A, 354: 1333–1360.CrossRefGoogle Scholar
  15. Knittle, E., and Jeanloz, R., 1991. The high pressure phase diagram of Fe0.94O: a possible constituent of the Earth's core. Journal of Geophysical Research, 96: 16169–16180.Google Scholar
  16. Kubo, A., Ito, E., Katsura, T., Shinmei, T., Yamada, H., Nishikawa, O., Song, M., and Funakoshi, K., 2003. Phase equilibrium study of iron using sintered diamond (SD) anvils: absence of beta phase. PEPI, 30: 1126.Google Scholar
  17. Ma, Y.Z., Somayazulu, M., Mao, H.K., Shu, J.F., Hemley, R.J., and Shen, G., 2004. In situ x‐ray diffraction studies of iron to the Earth core conditions. Physics of the Earth and Planetary Interiors, 144: 455–467.CrossRefGoogle Scholar
  18. Mao, H.K., Xu, J., and Bell, P.M., 1986. Calibration of the ruby pressure gauge to 800 kbar under quasi‐hydrostatic conditions. Journal of Geophysical Research, 91: 4673–4676.Google Scholar
  19. Mao, H.K., Bell, P.M., and Hadidiacos, C., 1987. Experimental phase relations of iron to 360 kbar and 1400 C, determined in an internally heated diamond anvil apparatus. In Manghnani, M.H., and Syono, Y. (eds.), High Pressure Research in Mineral Physics. Tokyo: Terra Scientific Publishing Company/American Geophysical Union, pp. 135–138.Google Scholar
  20. Nguyen, J.H., and Holmes, N.C., 2004. Melting of iron at the physical conditions of the Earth's core. Nature, 427: 339–342.CrossRefGoogle Scholar
  21. Ringwood, A.E., and Hibberson, W., 1990. The system Fe‐FeO revisited. Physics and Chemistry of Minerals, 17: 313–319.CrossRefGoogle Scholar
  22. Saxena, S.K., Shen, G., and Lazor, P., 1994. Temperatures in Earth's core based on melting and phase transformation experiments on iron. Science, 264: 405–407.CrossRefGoogle Scholar
  23. Saxena, S.K., Dubrovinsky, L.S., and Haggkvist, P., 1995. X‐ray evidence for the new phase β‐iron at high pressure and high temperature. Geophysical Research Letters, 23: 2441–2444.CrossRefGoogle Scholar
  24. Shen, G., Mao, H.K., Hemley, R.J., Duffy, T.S., and Rivers, M.L., 1998. Melting and crystal structure of iron at high pressures. Geophysical Research Letters, 25: 373–376.CrossRefGoogle Scholar
  25. Shen, G., Prakapenka, V.B., Rivers, M.L., and Sutton, S.R., 2004. Structure of liquid iron at pressures up to 58 GPa. Physical Review Letters, 92: 185701.CrossRefGoogle Scholar
  26. Urakawa, S., Kato, M., and Kumazawa, M., 1987. Experimental study of the phase relation in the system Fe‐Ni‐O‐S up to 15 GPa. In Manghnani, M.H., and Syono, Y. (eds.), High Pressure Research in Mineral Physics. Tokyo: Terra Scientific Publishing Company, pp. 95–111.Google Scholar
  27. Usselmann, T.M., 1975. Experimental approach to the state of the core. I. The liquidus relations of the Fe‐rich portion of the Fe‐Ni‐S system from 30 to 100 kb. American Journal of Science, 275: 278–290.CrossRefGoogle Scholar
  28. Williams, Q., Knittle, E., and Jeanloz, R., 1991. The high pressure melting curve of iron: a technical discussion. Journal of Geophysical Research, 96: 2171–2184.Google Scholar
  29. Xu, J., Mao, H.K., and Bell, P.M., 1986. High pressure ruby and diamond fluorescence: observations at 0.21 to 0.55 TPa. Science, 232: 1404–1406.CrossRefGoogle Scholar

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  • Guoyin Shen

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