Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 4 May 2001:
Vol. 292. no. 5518, pp. 914 - 916
DOI: 10.1126/science.1057670
Prev | Table of Contents | Next

Reports

Phonon Density of States of Iron up to 153 Gigapascals

H. K. Mao,1 J. Xu,1 V. V. Struzhkin,1 J. Shu,1 R. J. Hemley,1 W. Sturhahn,2 M. Y. Hu,2 E. E. Alp,2 L. Vocadlo,3 D. Alfè,3 G. D. Price,3 M. J. Gillan,3 M. Schwoerer-Böhning,4 D. Häusermann,4 P. Eng,5 G. Shen,5 H. Giefers,6 R. Lübbers,6 G. Wortmann6

We report phonon densities of states (DOS) of iron measured by nuclear resonant inelastic x-ray scattering to 153 gigapascals and calculated from ab initio theory. Qualitatively, they are in agreement, but the theory predicts density at higher energies. From the DOS, we derive elastic and thermodynamic parameters of iron, including shear modulus, compressional and shear velocities, heat capacity, entropy, kinetic energy, zero-point energy, and Debye temperature. In comparison to the compressional and shear velocities from the preliminary reference Earth model (PREM) seismic model, our results suggest that Earth's inner core has a mean atomic number equal to or higher than pure iron, which is consistent with an iron-nickel alloy.

1 Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, Washington, DC 20015, USA.
2 Advanced Photon Source, Argonne, IL 60439, USA.
3 University College London, Gower Street, London WC1E 6BT, UK.
4 High Pressure Collaborative Access Team (HPCAT), Advanced Photon Source, Argonne, IL 60439, USA.
5 Consortium for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637.
6 Fachbereich Physik, University of Paderborn, D33095 Paderborn, Germany.

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Elasticity measurements on minerals: a review.
R. J. Angel, J. M. Jackson, H. J. Reichmann, and S. Speziale (2009)
European Journal of Mineralogy 21, 525-550
   Abstract »    Full Text »    PDF »
Nuclear resonant X-ray spectroscopy of (Mg,Fe)SiO3 orthoenstatites.
J. M. Jackson, E. A. Hamecher, and W. Sturhahn (2009)
European Journal of Mineralogy 21, 551-560
   Abstract »    Full Text »    PDF »
Equilibrium Iron Isotope Fractionation at Core-Mantle Boundary Conditions.
V. B. Polyakov (2009)
Science 323, 912-914
   Abstract »    Full Text »    PDF »
High-Pressure Geoscience Special Feature: Thermal expansion of iron-rich alloys and implications for the Earth's core.
B. Chen, L. Gao, K.-i. Funakoshi, and J. Li (2007)
PNAS 104, 9162-9167
   Abstract »    Full Text »    PDF »
Geophysical applications of nuclear resonant spectroscopy.
W. Sturhahn and J. M. Jackson (2007)
Geological Society of America Special Papers 421, 157-174
   Abstract »    Full Text »    PDF »
Sound Velocities of Hot Dense Iron: Birch's Law Revisited.
J.-F. Lin, W. Sturhahn, J. Zhao, G. Shen, H.-k. Mao, and R. J. Hemley (2005)
Science 308, 1892-1894
   Abstract »    Full Text »    PDF »
A synchrotron Mossbauer spectroscopy study of (Mg,Fe)SiO3 perovskite up to 120 GPa.
J. M. Jackson, W. Sturhahn, G. Shen, J. Zhao, M. Y. Hu, D. Errandonea, J. D. Bass, and Y. Fei (2005)
American Mineralogist 90, 199-205
   Abstract »    Full Text »    PDF »
Robust Normal Mode Constraints on Inner-Core Anisotropy from Model Space Search.
C. Beghein and J. Trampert (2003)
Science 299, 552-555
   Abstract »    Full Text »    PDF »
New windows on earth and planetary interiors.
R. J. Hemley and H. K. Mao (2002)
Mineralogical Magazine 66, 791-811
   Abstract »    Full Text »    PDF »
Iron-Silicon Alloy in Earth's Core?.
J.-F. Lin, D. L. Heinz, A. J. Campbell, J. M. Devine, and G. Shen (2002)
Science 295, 313-315
   Abstract »    Full Text »    PDF »
Aggregate sound velocities and acoustic Gruneisen parameter of iron up to 300 GPa and 1,200 K.
L. S. Dubrovinsky, N. A. Dubrovinskaia, and T. Le Bihan (2001)
PNAS 98, 9484-9489
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)