Reviews of topical problems

Universal viscosity growth in metallic melts at megabar pressures: the vitreous state of the Earth’s inner core

 a,  b
a Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russian Federation
b Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russian Federation

Experimental data on and theoretical models for the viscosity of various types of liquids and melts under pressure are reviewed. Experimentally, the least studied melts are those of metals, whose viscosity is considered to be virtually constant along the melting curve. The authors’ new approach to the viscosity of melts involves the measurement of the grain size in solidified samples. Measurements on liquid metals at pressures up to 10 GPa using this method show, contrary to the empirical approach, that the melt viscosity grows considerably along the melting curves. Based on the experimental data and on the critical analysis of current theories, a hypothesis of a universal viscosity behavior is introduced for liquids under pressure. Extrapolating the liquid iron results to the pressures and temperatures at the Earth’s core reveals that the Earth’s outer core is a very viscous melt with viscosity values ranging from 102 Pa s to 1011 Pa s depending on the depth. The Earth’s inner core is presumably an ultraviscous (>1011 Pa s) glass-like liquid — in disagreement with the current idea of a crystalline inner core. The notion of the highly viscous interior of celestial bodies sheds light on many mysteries of planetary geophysics and astronomy. From the analysis of the pressure variation of the melting and glass-transition temperatures, an entirely new concept of a stable metallic vitreous state arises, calling for further experimental and theoretical study.

Fulltext is available at IOP
PACS: 61.25.Mv, 61.43.−j, 62.50.+p, 66.20.+d, 91.35.Ed (all)
DOI: 10.1070/PU2000v043n05ABEH000682
Citation: Brazhkin V V, Lyapin A G "Universal viscosity growth in metallic melts at megabar pressures: the vitreous state of the Earth's inner core" Phys. Usp. 43 493–508 (2000)
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Оригинал: Бражкин В В, Ляпин А Г «Универсальный рост вязкости металлических расплавов в мегабарном диапазоне давлений: стеклообразное состояние внутреннего ядра Земли» УФН 170 535–551 (2000); DOI: 10.3367/UFNr.0170.200005c.0535

References (126) Cited by (54) Similar articles (20) ↓

  1. V.N. Mineev, A.I. Funtikov “Viscosity measurements on metal melts at high pressure and viscosity calculations for the earth’s core47 671–686 (2004)
  2. S.M. Stishov “The thermodynamics of melting of simple substances18 625–643 (1975)
  3. L.V. Al’tshuler “Use of shock waves in high-pressure physics8 52–91 (1965)
  4. V.V. Brazhkin, A.G. Lyapin et alWhere is the supercritical fluid on the phase diagram?55 1061–1079 (2012)
  5. L.V. Al’tshuler, A.A. Bakanova “Electronic structure and compressibility of metals at high pressures11 678–689 (1969)
  6. A.Z. Dolginov “Origin of the magnetic fields of the earth and celestial bodies30 475–493 (1987)
  7. D.K. Belashchenko “Diffusion mechanisms in disordered systems: computer simulation42 297–319 (1999)
  8. V.M. Svistunov, M.A. Belogolovskii, O.I. Chernyak “Tunnel investigations of metals at high pressures30 1–22 (1987)
  9. I.L. Fabelinskii “Macroscopic and molecular shear viscosity40 689–700 (1997)
  10. S.M. Stishov “Melting at high pressures11 816–830 (1969)
  11. R.F. Trunin “Shock compression of condensed materials (laboratory studies)44 371–396 (2001)
  12. R. Folk, Yu. Holovatch, T. Yavorskii “Critical exponents of a three-dimensional weakly diluted quenched Ising model46 169–191 (2003)
  13. D.K. Belashchenko “Computer simulation of liquid metals56 1176–1216 (2013)
  14. N.B. Brandt, E.S. Itskevich, N.Ya. Minina “Influence of pressure on the Fermi surface of metals14 438–454 (1972)
  15. A.I. Voropinov, G.M. Gandel’man, V.G. Podval’nyi “Electronic energy spectra and the equation of state of solids at high pressures and temperatures13 56–72 (1970)
  16. N.B. Brandt, N.I. Ginzburg “Effect of high pressure on the superconducting properties of metals8 202–223 (1965)
  17. G.V. Kozlov, V.U. Novikov “A cluster model for the polymer amorphous state44 681–724 (2001)
  18. G.I. Kanel, V.E. Fortov, S.V. Razorenov “Shock waves in condensed-state physics50 771–791 (2007)
  19. V.A. Gritsenko “Atomic structure of the amorphous nonstoichiometric silicon oxides and nitrides51 699–708 (2008)
  20. A.I. Gusev “Nonstoichiometry and superstructures57 839–876 (2014)

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