Phonon Density of States of Iron up to 153 Gigapascals

• DOI: 10.1126/science.1057670
• Publication Date: 2002-07-27T09:52:41Z
• Authors: H. K. Mao; J. Xu; V. V. Struzhkin; J. Shu; R. J. Hemley; W. Sturhahn; M. Y. Hu; E. E. Alp; L. Vocadlo; D. Alfè; G. D. Price; M. J. Gillan; M. Schwoerer-Böh...; D. Häusermann; P. Eng; G. Shen; H. Giefers; R. Lübbers; G. Wortmann
• Keywords: Debye model; Shear modulus; Debye; Density of states

We report phonon densities of states (DOS) 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 DOS, we derive elastic thermodynamic parameters iron, including shear modulus, compressional velocities, heat capacity, entropy, kinetic energy, zero-point Debye temperature. In comparison velocities preliminary reference Earth model (PREM) seismic model, our results suggest that Earth's inner core has a mean atomic number equal or than pure which is consistent with an iron-nickel alloy.