Physics and Chemistry of Minerals

, Volume 45, Issue 6, pp 589–595 | Cite as

Measurements of sound velocity in iron–nickel alloys by femtosecond laser pulses in a diamond anvil cell

  • Tatsuya WakamatsuEmail author
  • Kenji OhtaEmail author
  • Takashi Yagi
  • Kei Hirose
  • Yasuo Ohishi
Original Paper


By comparing the seismic wave velocity profile in the Earth with laboratory data of the sound velocity of iron alloys, we can infer the chemical composition of materials in the Earth’s core. The sound velocity of pure iron (Fe) has been sufficiently measured using various techniques, while experimental study on the sound velocity of iron–nickel (Fe–Ni) alloys is limited. Here, we measured longitudinal wave velocities of hexagonal-close-packed (hcp) structured Fe up to 29 GPa, Fe–5 wt% Ni, and Fe–15 wt% Ni up to 64 GPa via a combination of the femtosecond pulse laser pump–probe technique and a diamond anvil cell at room temperature condition. We found that the effect of Ni on the sound velocity of an Fe-based alloy is weaker than that determined by previous experimental study. In addition, we obtained the parameters of Birch’s law to be VP = 1146(57)ρ − 3638(567) for Fe–5 wt% Ni and VP = 1141(45)ρ− 3808(446) for Fe–15 wt% Ni, respectively, where VP is longitudinal wave velocity (m/s) and ρ is density (g/cm3).


Earth’s core Sound velocity measurement High pressure Iron–nickel alloy Femtosecond pulse laser pump–probe technique Diamond anvil cell 



We thank Dr. Alexander F. Goncharov and Dr. Junichi Nakajima for their technical advice. Phase identification of our samples at high pressures was performed by means of synchrotron X-ray diffraction measurements at BL10XU, SPring-8 (proposal no. 2016B0080).


  1. Akahama Y, Kawamura H (2004) High-pressure Raman spectroscopy of diamond anvils to 250 GPa: method for pressure determination in the multimegabar pressure range. J Appl Phys 96:3748–3751. CrossRefGoogle Scholar
  2. Antonangeli D, Ohtani E (2015) Sound velocity of hcp-Fe at high pressure: experimental constraints, extrapolations and comparison with seismic models. Prog Earth Planet Sci 2:1–11. CrossRefGoogle Scholar
  3. Antonangeli D, Komabayashi T, Occelli F et al (2012) Simultaneous sound velocity and density measurements of hcp iron up to 93 GPa and 1100 K: an experimental test of the Birch’s law at high temperature. Earth Planet Sc Lett 331:210–214. CrossRefGoogle Scholar
  4. Anzellini S, Dewaele A, Mezouar M et al (2013) Melting of iron at Earth’s inner core boundary based on fast X-ray diffraction. Science 340:464–466. CrossRefGoogle Scholar
  5. Badro J, Fiquet G, Guyot F et al (2007) Effect of light elements on the sound velocities in solid iron: implications for the composition of Earth’s core. Earth Planet Sci Lett 254:233–238. CrossRefGoogle Scholar
  6. Bass JD, Zhang JS (2015) Theory and practice: techniques for measuring high-P–T elasticity. Treatise Geophys Second Ed 293–312Google Scholar
  7. Birch F (1952) Elasticity and constitution of the Earth’s interior. J Geophys Res 57:227–286. CrossRefGoogle Scholar
  8. Caracas R (2015) The influence of hydrogen on the seismic properties of solid iron. Geophys Res Lett 42:3780–3785. CrossRefGoogle Scholar
  9. Decremps F, Antonangeli D, Gauthier M et al (2014) Sound velocity of iron up to 152 GPa by picosecond acoustics in diamond anvil cell. Geophys Res Lett 41:1459–1464. CrossRefGoogle Scholar
  10. Decremps F, Gauthier M, Ayrinhac S et al (2015) Picosecond acoustics method for measuring the thermodynamical properties of solids and liquids at high pressure and high temperature. Ultrasonics 56:129–140. CrossRefGoogle Scholar
  11. Dewaele A, Loubeyre P, Occelli F et al (2006) Quasihydrostatic equation of state of iron above 2 Mbar. Phys Rev Lett 97:215504. CrossRefGoogle Scholar
  12. Dziewonski AM, Anderson DL (1981) Preliminary reference Earth model. Phys Earth Planet Inter 25:297–356. CrossRefGoogle Scholar
  13. Elardo S, Shahar A (2017) Non-chondritic iron isotope ratios in planetary mantles as a result of core formation. Nat Geosci 10:17–321. CrossRefGoogle Scholar
  14. Fiquet G, Badro J, Guyot F et al (2001) Sound velocities in iron to 110 gigapascals. Science 291:468–471. CrossRefGoogle Scholar
  15. Fiquet G, Badro J, Gregoryanz E et al (2009) Sound velocity in iron carbide (Fe3C) at high pressure: implications for the carbon content of the Earth’s inner core. Phys Earth Planet Inter 172:125–129. CrossRefGoogle Scholar
  16. Guinan MW, Beshers DN (1968) Pressure derivatives of the elastic constants of α-iron to 10 kbs. J Phys Chem Solids 29:541–549. CrossRefGoogle Scholar
  17. Kamada S, Ohtani E, Fukui H et al (2014) The sound velocity measurements of Fe3S. Am Mineral 99:98–101. CrossRefGoogle Scholar
  18. Kantor A, Kantor I, Kurnosov A et al (2007) Sound wave velocities of fcc Fe–Ni alloy at high pressure and temperature by mean of inelastic X-ray scattering. Phys Earth Planet Inter 164:83–89. CrossRefGoogle Scholar
  19. Li J, Fei Y (2007) Experimental constraints on core composition. Treatise on geochemistry. Elsevier, New York, pp 1–31Google Scholar
  20. Lin J-F, Struzhkin VV, Sturhahn W et al (2003) Sound velocities of iron–nickel and iron-silicon alloys at high pressures. Geophys Res Lett 30:2112. CrossRefGoogle Scholar
  21. Lin J-F, Sturhahn W, Zhao J et al (2005) Sound velocities of hot dense iron: Birch’s law revisited. Science 308:1892–1894. CrossRefGoogle Scholar
  22. Liu J, Dauphas N, Roskosz M et al (2017) Iron isotopic fractionation between silicate mantle and metallic core at high pressure. Nat Commun 8:14377. CrossRefGoogle Scholar
  23. Mao H, Wu Y, Chen L et al (1990) Static compression of iron to 300 GPa and Fe0.8Ni0.2 alloy to 260 GPa: implications for composition of the core. J Geophys Res 95:21737–21742. CrossRefGoogle Scholar
  24. Mao W, Sturhahn W, Heinz D et al (2004) Nuclear resonant X-ray scattering of iron hydride at high pressure. Geophys Res Lett 31:L15618. CrossRefGoogle Scholar
  25. Mao Z, Lin J-F, Liu J et al (2012) Sound velocities of Fe and Fe–Si alloy in the Earth’s core. Proc Natl Acad Sci USA 109:10239–10244. CrossRefGoogle Scholar
  26. Martorell B, Brodholt J, Wood I et al (2013) The effect of nickel on the properties of iron at the conditions of Earth’s inner core: Ab initio calculations of seismic wave velocities of Fe–Ni alloys. Earth Planet Sci Lett 365:143–151. CrossRefGoogle Scholar
  27. Ohtani E, Shibazaki Y, Sakai T et al (2013) Sound velocity of hexagonal close-packed iron up to core pressures. Geophys Res Lett 40:5089–5094. CrossRefGoogle Scholar
  28. Prescher C, Dubrovinsky L, Bykova E et al (2015) High Poisson’s ratio of Earth’s inner core explained by carbon alloying. Nat Geosci 8:220–223. CrossRefGoogle Scholar
  29. Robie RA, Hemingway BS, Fisher JR (1978) Thermodynamic properties of minerals and related substances at 298.15K and 1 bar (105pascals) pressure and at higher temperatures. US Geol Surv Bull 1452:12–29Google Scholar
  30. Sakai T, Takahashi S, Nishitani N et al (2014) Equation of state of pure iron and Fe0.9Ni0.1 alloy up to 3 Mbar. Phys Earth Planet Inter 228:114–126. CrossRefGoogle Scholar
  31. Sakamaki T, Ohtani E, Fukui H et al (2016) Constraints on Earth’s inner core composition inferred from measurements of the sound velocity of hcp-iron in extreme conditions. Sci Adv 2:e1500802. CrossRefGoogle Scholar
  32. Shibazaki Y, Ohtani E, Fukui H et al (2012) Sound velocity measurements in dhcp-FeH up to 70 GPa with inelastic X-ray scattering: implications for the composition of the Earth’s core. Earth Planet Sci Lett 313–314:79–85. CrossRefGoogle Scholar
  33. Singh SC, Taylor MAJ, Montagner JP (2000) On the presence of liquid in Earth’s inner core. Science 287:2471–2474. CrossRefGoogle Scholar
  34. Sossi P (2017) Planetary science: a nickel for your planet’s thoughts. Nat Geosci 10:249–251. CrossRefGoogle Scholar
  35. Takahashi T, Bassett W, Mao H (1968) Isothermal compression of the alloys of iron up to 300 kilobars at room temperature: iron–nickel alloys. J Geophys Res 73:4717–4725. CrossRefGoogle Scholar
  36. Terasaki H, Kamada S, Sakai T et al (2011) Liquidus and solidus temperatures of a Fe–O–S alloy up to the pressures of the outer core: implication for the thermal structure of the Earth’s core. Earth Planet Sci Lett 304:559–564. CrossRefGoogle Scholar
  37. Umemoto K, Hirose K (2015) Liquid iron-hydrogen alloys at outer core conditions by first-principles calculations. Geophys Res Lett 42:7513–7520. CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Earth and Planetary SciencesTokyo Institute of TechnologyTokyoJapan
  2. 2.National Metrology Institute of JapanNational Institute of Advanced Industrial Science and TechnologyIbarakiJapan
  3. 3.Earth-Life Science InstituteTokyo Institute of TechnologyTokyoJapan
  4. 4.Japan Synchrotron Radiation Research InstituteHyogoJapan

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