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From the current literature


Fe — C and Fe — H systems at pressures of the Earth’s inner core

 a,  b,  c
a Scientific Research Computer Center, Lomonosov Moscow State University, Leninskiye Gory 1, building 4, Moscow, 119991, Russian Federation
b Department of Geosciences and Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York, USA
c Institut für Geochemie und Petrologie, Department of Earth Sciences, ETH Zürich, Clausiusstrasse 25, 8092, Zürich, Switzerland

The solid inner core of Earth is predominantly composed of iron alloyed with several percent Ni and some lighter elements, Si, S, O, H, and C being the prime candidates. To establish the chemical composition of the inner core, it is necessary to find the range of compositions that can explain its observed characteristics. Recently, there have been a growing number of papers investigating C and H as possible light elements in the core, but the results were contradictory. Here, using ab initio simulations, we study the Fe—C and Fe—H systems at inner core pressures (330–364 GPa). Based on the evolutionary structure prediction algorithm USPEX, we have determined the lowest-enthalpy structures of all possible carbides (FeC, Fe2C, Fe3C, Fe4C, FeC2, FeC3, FeC4, Fe7C3) and hydrides (Fe4H, Fe3H, Fe2H, FeH, FeH2, FeH3, FeH4) and have found that Fe2C (space group Pnma) is the most stable iron carbide at pressures of the inner core, while FeH, FeH3, and FeH4 are the most stable iron hydrides at these conditions. For Fe3C, the cementite structure (space group Pnma) and the Cmcm structure recently found by random sampling are less stable than the I-4 and C2 /m structures predicted here. We have found that FeH3 and FeH4 adopt chemically interesting thermodynamically stable crystal structures, containing trivalent iron in both compounds. We find that the density of the inner core can be matched with a reasonable concentration of carbon, 11–15 mol.% (2.6–3.7 wt.%) at relevant pressures and temperatures, yielding the upper bound to the C content in the inner core. This concentration matches that in CI carbonaceous chondrites and corresponds to the average atomic mass in the range 49.3–51.0, in close agreement with inferences from Birch’s law for the inner core. Similarly made estimates for the maximum hydrogen content are unrealistically high: 17–22 mol.% (0.4–0.5 wt.%), which corresponds to the average atomic mass of the core in the range 43.8–46.5. We conclude that carbon is a better candidate light alloying element than hydrogen.

Fulltext pdf (1.6 MB)
Fulltext is also available at DOI: 10.3367/UFNe.0182.201205c.0521
PACS: 61.50.Ah, 61.50.Ks, 61.50.Nw, 61.66.Fn, 64.30.−t, 91.60.Fe (all)
DOI: 10.3367/UFNe.0182.201205c.0521
URL: https://ufn.ru/en/articles/2012/5/c/
000307559000003
2-s2.0-84864990959
2012PhyU...55..489B
Citation: Bazhanova Z G, Oganov A R, Gianola O "Fe — C and Fe — H systems at pressures of the Earth's inner core" Phys. Usp. 55 489–497 (2012)
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Received: 13th, December 2011, revised: 22nd, February 2012, 17th, February 2012

Оригинал: Бажанова З Г, Оганов А Р, Джанола О «Системы Fe — C и Fe — H при давлениях внутреннего ядра Земли» УФН 182 521–530 (2012); DOI: 10.3367/UFNr.0182.201205c.0521

References (72) Cited by (82) ↓ Similar articles (6)

  1. Deng Ju, Gou H, Hu Q Sci. Adv. 12 (19) (2026)
  2. Chen Q, Zhang F, Muir J M R JGR Solid Earth 131 (3) (2026)
  3. Quan H, Li Sh-N et al J. Mater. Chem. C 13 (2) 928 (2025)
  4. Satyal S, Wang J JGR Solid Earth 130 (10) (2025)
  5. Huang Yu-Q, Niu Zh-W, Tang M Solid State Communications 383 115482 (2024)
  6. Wang Yu, Chen S et al Phys. Chem. Chem. Phys. 26 (9) 7371 (2024)
  7. Tahmasbi H, Ramakrishna K et al Phys. Rev. Materials 8 (3) (2024)
  8. Zagorac D, Zagorac Je et al Procedia Structural Integrity 54 446 (2024)
  9. Fu Ch, Li W et al Solid State Communications 368 115180 (2023)
  10. Yang H, Muir J M R, Zhang F American Mineralogist 108 (4) 667 (2023)
  11. Anisichkin V F Izv., Phys. Solid Earth 59 (2) 135 (2023)
  12. Kemper J, Khan A et al Geophysical Journal International 235 (1) 690 (2023)
  13. Gavrilyuk A G, Troyan I A et al Pisʹma V žurnal êksperimentalʹnoj I Teoretičeskoj Fiziki 118 (9-10 (11)) 735 (2023)
  14. Gavriliuk A G, Troyan I A et al Jetp Lett. 118 (10) 742 (2023)
  15. Anisichkin V F Fizika Zemli (2) 36 (2023)
  16. Pushcharovsky D Yu Crystallogr. Rep. 68 (S1) S41 (2023)
  17. Pushcharovsky D Yu Crystallogr. Rep. 68 (S1) S18 (2023)
  18. Huang Yu, Hou M et al JGR Solid Earth 127 (4) (2022)
  19. Wakamatsu T, Ohta K et al Phys Chem Minerals 49 (5) (2022)
  20. Schlichting H E, Young E D Planet. Sci. J. 3 (5) 127 (2022)
  21. Yang H, Muir J M R, Zhang F Geochem Geophys Geosyst 23 (12) (2022)
  22. Troyan I A, Semenok D V et al Phys. Usp. 65 (07) 748 (2022)
  23. Gavriliuk A G, Struzhkin V V et al Jetp Lett. 116 (11) 804 (2022)
  24. Sagatov N E, Abuova A U et al RSC Adv. 11 (53) 33781 (2021)
  25. Kong P, Wang J et al Phys. Chem. Chem. Phys. 23 (27) 14671 (2021)
  26. Sagatov N E, Sagatova D N et al Crystal Growth & Design 21 (11) 6101 (2021)
  27. Wang W, Li Yu et al Earth And Planetary Science Letters 568 117014 (2021)
  28. Liu W-H, Zeng W et al Physica B: Condensed Matter 606 412825 (2021)
  29. Yuan X, Zhou Yu et al J. Phys. Chem. C 124 (31) 17244 (2020)
  30. Binns Ja, He Yu et al J. Phys. Chem. Lett. 11 (9) 3390 (2020)
  31. Sagatov N E, Gavryushkin P N et al Russian Geology and Geophysics 61 (12) 1345 (2020)
  32. Skoczylas K M, Durajski A P, Szczȩśniak R Physica B: Condensed Matter 584 412063 (2020)
  33. Kato Ch, Umemoto K et al American Mineralogist 105 (6) 917 (2020)
  34. Sagatova D N, Gavryushkin P N et al Jetp Lett. 111 (3) 145 (2020)
  35. Peña-Alvarez M, Li B et al J. Phys. Chem. Lett. 11 (15) 6420 (2020)
  36. Li J, Chen B et al Deep Carbon 1 3 (2019) p. 40
  37. Hermann A Chinese Phys. B 28 (10) 106107 (2019)
  38. Charraud Je-B, Geneste G, Torrent M Phys. Rev. B 100 (22) (2019)
  39. Gao P, Su Ch et al New J. Chem. 43 (44) 17403 (2019)
  40. Pushcharovsky D Yu Geochem. Int. 57 (9) 941 (2019)
  41. Robson A J S, Romanowicz B Physics Of The Earth And Planetary Interiors 295 106310 (2019)
  42. Sagatov N, Gavryushkin P N et al RSC Adv. 9 (7) 3577 (2019)
  43. Bi T, Zarifi N et al Reference Module in Chemistry, Molecular Sciences and Chemical Engineering (2019)
  44. Zhang Sh, Lin J et al J. Phys. Chem. C 122 (22) 12022 (2018)
  45. Zheng Sh, Zhang Sh et al Front. Phys. 6 (2018)
  46. Li Yu, Vočadlo L, Brodholt J P Earth And Planetary Science Letters 493 118 (2018)
  47. Kvashnin A G, Kruglov I A et al J. Phys. Chem. C 122 (8) 4731 (2018)
  48. González-Hernández A G, Diaz Y, González-Hernández R J. Phys.: Conf. Ser. 1119 012010 (2018)
  49. Zarifi N, Bi T et al J. Phys. Chem. C 122 (42) 24262 (2018)
  50. Wang L, Duan D et al Inorg. Chem. 57 (1) 181 (2018)
  51. Felix V K Geochem. Int. 56 (12) 1117 (2018)
  52. Chen B, Lai X et al Earth And Planetary Science Letters 494 164 (2018)
  53. Bazhanova Z G, Roizen V V, Oganov A R Uspekhi Fizicheskikh Nauk 187 (10) 1105 (2017) [Bazhanova Z G, Roizen V V, Oganov A R Phys.-Usp. 60 (10) 1025 (2017)]
  54. Pépin C M, Geneste G et al Science 357 (6349) 382 (2017)
  55. Ma Ya, Duan D et al Phys. Chem. Chem. Phys. 19 (40) 27406 (2017)
  56. Leineweber A, Hickel T et al Acta Materialia 140 433 (2017)
  57. Kaminsky F V The Earth’s Lower Mantle Springer Geology Chapter 9 (2017) p. 281
  58. Litasov K D, Shatskiy A et al JGR Solid Earth 122 (5) 3574 (2017)
  59. Caracas R Geophysical Research Letters 44 (1) 128 (2017)
  60. Li F, Wang D et al RSC Adv. 7 (21) 12570 (2017)
  61. Chihi T, Bouhemadou A et al Chinese Journal Of Physics 55 (3) 977 (2017)
  62. Liu J, Lin Jung‐Fu et al Geophysical Research Letters 43 (24) (2016)
  63. Murphy C A Deep Earth Geophysical Monograph Series 1 (2016) p. 253
  64. Zhang Sh, Zhu L et al Inorg. Chem. 55 (21) 11434 (2016)
  65. Kuopanportti P, Hayward E et al Computational Materials Science 111 525 (2016)
  66. Liu Yu, Duan D et al Phys. Chem. Chem. Phys. 18 (3) 1516 (2016)
  67. Li Y, Vočadlo L et al JGR Solid Earth 121 (8) 5828 (2016)
  68. Caracas R Deep Earth Geophysical Monograph Series 1 (2016) p. 55
  69. Chen B, Li J Deep Earth Geophysical Monograph Series 1 (2016) p. 277
  70. Litasov K D, Shatskiy A F Russian Geology and Geophysics 57 (1) 22 (2016)
  71. Woerner W R, Qian G-R et al Inorg. Chem. 55 (7) 3384 (2016)
  72. Raza Z, Shulumba N et al Phys. Rev. B 91 (21) (2015)
  73. Pépin Ch, Loubeyre P et al Proc. Natl. Acad. Sci. U.S.A. 112 (25) 7673 (2015)
  74. Litasov K D, Popov Z I et al Russian Geology and Geophysics 56 (1-2) 164 (2015)
  75. Struzhkin V V Physica C: Superconductivity And Its Applications 514 77 (2015)
  76. Sobolev N V, Dobretsov N L et al Russian Geology and Geophysics 56 (1-2) 1 (2015)
  77. Fei Y, Brosh E Earth And Planetary Science Letters 408 155 (2014)
  78. Revard B C, Tipton W W, Hennig R G Topics In Current Chemistry Vol. Prediction and Calculation of Crystal StructuresStructure and Stability Prediction of Compounds with Evolutionary Algorithms345 Chapter 489 (2014) p. 181
  79. Belashchenko D K Geochem. Int. 52 (6) 456 (2014)
  80. Pépin Ch M, Dewaele A et al Phys. Rev. Lett. 113 (26) (2014)
  81. Litasov K D, Sharygin I S et al JGR Solid Earth 118 (10) 5274 (2013)
  82. Belashchenko D K Phys.-Usp. 56 (12) 1176 (2013)
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