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REVIEW 3 major objections 5 minor 61 references

Observation of Body-Centered Cubic Iron above 200 Gigapascals

T0 review · 3 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash

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Pith's one-line read X-ray diffraction data show body-centered cubic iron appearing near the melting line above 200 GPa.

desk verdict Credible first experimental evidence for bcc Fe above 200 GPa, honestly hedged; the observation is solid but whether it is the entropically stabilized phase or a metastable quench product remains open. read the letter →

arxiv 2505.15397 v1 pith:XI2VLOL6 submitted 2025-05-21 cond-mat.mtrl-sci

Zuzana Konopkova , Eric Edmund , Orianna B Ball , Agnes Dewaele , Helene Ginestet , Rachel J Husband , Nicolas Jaisle , Cornelius Strohm
show 29 more authors
Madden S Anae Daniele Antonangeli Karen Appel Marzena Baron Silvia Boccato Khachiwan Buakor Julien Chantel Hyunchae Cynn Anand P Dwivedi Lars Ehm Konstantin Glazyrin Heinz Graafsma Egor Koemets Torsten Laurus Hauke Marquardt Bernhard Massani James D McHardy Malcolm I McMahon Vitali Prakapenka Jolanta Sztuk-Dambietz Minxue Tang Tianqi Xie Zena Younes Ulf Zastrau Alexander F Goncharov Clemens Prescher Ryan S McWilliams Guillaume Morard Sebastien Merkel
This is my paper · ORCID
classification cond-mat.mtrl-sci
keywords bccironphasediagramMHzX-raydiffractiondiamondanvilcellEarth'sinnercorehighpressuremeltingcurveentropicstabilization
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper reports an experimental observation of body-centered cubic (bcc) iron at pressures above 200 GPa, near the melting line. Using MHz X-ray pulses to heat and probe a diamond-anvil-cell sample, the authors saw a single new diffraction peak appear at high temperature and place the bcc phase at 233-246 GPa and 4000-5000 K. They identify the peak as the 110 reflection of bcc iron by ruling out fcc indexing on volume and peak-count grounds. If the phase is stable rather than a product of rapid cooling, it would add a bcc field to iron's phase diagram and change how the freezing and structure of Earth's inner core are modeled.

What carries the argument

The load-bearing object is a single extra diffraction line that appears halfway between the 002 and 101 reflections of hcp iron in the integrated X-ray patterns. The whole identification rests on indexing this line as the 110 reflection of bcc iron: it is the only assignment that yields a physically plausible volume and predicts exactly one visible new reflection, with the next bcc line, 200, outside the detector's angular range. This indexing is supported by a finite element heat-flow model and streaked optical pyrometry that place the diffraction snapshot at the minimum of a heating-cooling cycle, after peak temperatures that may exceed the melting line, and by a proposed growth mechanism in which bcc nucleates as nanotwins in the hcp matrix and then de-twins into polycrystalline grains.

What would settle it

A decisive test would be a laser-heated diamond-anvil-cell experiment at 233-246 GPa that holds pure iron at 4000-5000 K long enough to approach equilibrium and then cools it slowly while monitoring diffraction: if the bcc 110 peak vanishes or never appears under slow cooling and sustained heating, the reported bcc phase is a kinetic or nonthermal product rather than an equilibrium phase near the melting curve.

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Extended reading notes

Core claim

The central claim is that pure iron transforms from the hexagonal close-packed structure to a body-centered cubic structure in a narrow band just below the melting curve at 233-246 GPa and 4000-5000 K. The evidence is a new X-ray reflection that appears between the hcp 002 and 101 lines during the hottest part of each heating-cooling cycle, intensifies as the hcp reflections weaken, and disappears after quenching. The paper argues it cannot be fcc: the 111 fcc indexing would require a volume 7 percent smaller than the 300 K hcp value, an implausibly large change, and the 200 fcc reflection should be visible but is not. The 110 bcc indexing gives a volume only 1.3 percent above 300 K hcp and places the next bcc reflection outside the detector range. The authors propose that the bcc structure is entropically stabilized near melting, note that the positive hcp-bcc volume change implies a flat or positive Clapeyron slope, and leave open whether what they observed is the equilibrium phase or a metastable phase formed during rapid cooling from the melt or by nonthermal electronic excitation.

Load-bearing premise

The result stands or falls on whether the bcc signal captured at the coolest moment of each cycle, after a temperature drop of as much as 2000 K at cooling rates near 10 K per nanosecond, represents a phase that belongs near the melting line rather than a temporary structure that only appears under those extreme cooling conditions or because the X-ray pulse excites electrons before the lattice heats up.

Editorial extensions

If this is right

  • If the bcc phase is stable near melting above 200 GPa, iron's phase diagram gains an hcp-bcc-liquid triple point in this pressure range, with the hcp-bcc boundary having a flat or positive Clapeyron slope because the measured hcp-bcc volume change is positive.
  • At Earth's inner core conditions, the bcc phase could be the solid that crystallizes from the liquid outer core, offering a structural explanation for the small-scale anisotropy and relatively isotropic outer shell of the inner core.
  • The existence of an intermediate bcc phase between hcp iron and liquid iron would raise the inferred melting temperature at inner core conditions, since the entropy changes across hcp-bcc and bcc-liquid transitions must sum to at least the entropy change of the lower-pressure hcp-liquid transition.
  • Compositional and seismic models that take hcp iron for granted at core conditions would need revision, because light-element partitioning and elastic properties differ between hcp and bcc lattices.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Editorial inference: the observed bcc phase may be specific to the experiment's cooling pathway; because Earth's inner core freezes over geological time, slow cooling could still select hcp, so the geophysical significance depends on whether the bcc field is equilibrium or a kinetic artifact.
  • Editorial inference: the same MHz-pulse experiment could map the kinetic-stability boundary directly by changing the pulse spacing or train length to vary cooling rate; if the bcc fraction tracks cooling rate rather than peak temperature, that would identify it as a metastable solidification product.
  • Editorial inference: the nonthermal electronic route could be separated from the thermal route by probing diffraction within picoseconds after a single X-ray pulse, before electron-ion equilibration, to test whether the bcc structure appears in a cold lattice, as predicted for fcc iron at ambient pressure.
  • Editorial inference: the observed competition among hcp, fcc, and bcc on cooling across 122-218 GPa resembles polymorphic phase selection during rapid solidification, and a systematic pressure-temperature-cooling-rate survey would provide benchmarks for atomistic simulations of iron's phase stability.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 5 minor

Summary. The manuscript reports time-resolved X-ray diffraction of iron compressed in a diamond anvil cell to 208-218 GPa and heated by MHz-rate X-ray pulses at the European XFEL. A new diffraction line appears at high temperatures between the hcp 002 and 101 reflections; the authors index it as the 110 reflection of a body-centered cubic phase and place the transition at 233-246 GPa and 4000-5000 K using the thermal equation of state of Dewaele et al. They interpret the phase as entropically stabilized near melting, discuss analogies to metastable solidification, and draw implications for the Earth's inner core. The paper also reports transient bcc/fcc behavior at lower pressures.

Significance. If the bcc assignment holds, this is the first experimental evidence for bcc iron at core pressures and would provide a valuable constraint for theoretical phase diagrams and for the interpretation of inner-core seismology. The experimental approach—volumetric MHz X-ray heating with pulse-by-pulse diffraction—is a notable technical step forward, and the manuscript is unusually transparent about its limitations, including the cooling between peak temperature and the diffraction snapshot, possible metastable solidification, and nonthermal electronic effects. The two-sample reproducibility and the promise of open data are additional strengths. However, because the diffraction evidence is a single reflection and the thermodynamic stability is inferred rather than demonstrated, the significance, while potentially high, is not yet established.

major comments (3)
  1. [Results, paragraph beginning 'The individual Bragg reflections'] The bcc assignment rests on a single observed reflection, with fcc excluded on the basis of an implausible volume and the absence of the 200 line. To make this identification load-bearing, the paper should state the full accessible 2θ range and list the predicted positions and relative intensities of the first several reflections for all plausible Fe structures (hcp, fcc, bcc, and any other high-symmetry candidate). As written, the text does not quantitatively rule out other structures whose first allowed reflection could fall in this angular window. A table or figure comparing candidate structures against the observed d-spacing and the accessible range would substantially strengthen the assignment.
  2. [FEA paragraph and Fig. 3 discussion] The central interpretation as an entropically stabilized bcc phase near melting is not established by the data. The paper states that the X-ray diffraction snapshot is taken at the minimum temperature of each heating-cooling cycle, after a temperature drop of as much as 2000 K, and that part of the sample may have cooled from a liquid state; it also explicitly invokes Sadigh et al.'s metastable polymorphic solidification and raises the 'crucial question' of nonthermal transitions. These admissions are in tension with the abstract's claim of an 'entropically stabilized bcc structure.' To support the stability claim, the authors would need to show that the bcc phase persists under conditions where the sample has not passed through the melt or that its appearance is consistent with equilibrium nucleation, or alternatively to reframe the manuscript's conclusion as the observation of a bcc-like phase that may be metastable or transient. As written, the geophysical inferences in the final sections rest on a thermodynamic interpretation the data cannot yet distinguish from kinetic or nonthermal artifacts.
  3. [Table S2 and 'Our results place the formation...'] The reported pressure of 233-246 GPa and temperature of 4000-5000 K require an explicit uncertainty budget. The pressure is derived from measured hcp-Fe volumes using the Dewaele thermal EoS with an assumed temperature range, but the actual temperature at the diffraction snapshot is not directly measured; it is inferred from an average surface temperature from streaked pyrometry and a finite-element model. The paper does not state how the temperature uncertainty, the effect of thermal pressure, or variations during the pulse train propagate into the final pressure range. Without this, the confidence in the exact P-T location of the bcc field is difficult to assess, and this location is central to the claimed comparison with the iron phase diagram.
minor comments (5)
  1. [Results, fcc exclusion sentence] The comparison of the fcc 111 volume to the 'ambient temperature hcp structure' is confusing; the relevant reference is the hcp volume at the same high-temperature conditions, not at 300 K. The later statement that coexisting hcp and bcc volumes are 'roughly the same' (Fig. 2) is the more appropriate check, and the text should be clarified accordingly.
  2. [Caption for Movie S2] The caption says the movie shows data 'at pressures above 236 GPa,' but the sample (BetsaA) has a starting pressure of 152 GPa and the text describes behavior 'below 180 GPa.' Please correct this contradiction.
  3. [Results, Clapeyron slope sentence] The statement that a positive volume change implies a 'flat or positive' Clapeyron slope should justify the sign of the entropy change ΔS; as written, the reader must assume ΔS is positive, which is reasonable for a high-temperature phase but should be stated.
  4. [Figure 2] The density difference between hcp and bcc appears to be small, yet the regressions are shown without error bars or confidence intervals. Adding uncertainty estimates would make the claimed positive volume change more persuasive.
  5. [Results, paragraph on lower-pressure samples] The text says samples were studied 'at pressures below 180 GPa' and later that bcc is 'clearly stabilized' above 200 GPa, leaving an unaddressed gap between 180 and 200 GPa. Please clarify whether any data exist in this interval.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: the bcc assignment is a consistency check against measured diffraction geometry and external equations of state, not a fit; self-citations are instrument calibrations, not load-bearing.

full rationale

The paper's central claim is an experimental observation: a new diffraction line appears at high temperature and is indexed as the 110 reflection of bcc Fe. The indexing is justified by comparing candidate lattices against the measured d-spacing and the observed number of peaks: indexing as fcc 111 gives a volume 7% too low and would require a visible 200 reflection that is never observed, whereas bcc 110 gives a physically plausible volume 1.3% above 300 K hcp and places the 200 reflection outside the detector range. This is a consistency argument from measured 2θ positions, not a parameter fitted to the claimed result. Pressure is obtained from the externally published thermal equation of state of hcp-Fe (Dewaele et al., ref. 40) using measured hcp volumes; temperature is obtained from streaked optical pyrometry calibrated in a prior instrument paper (Ball et al., ref. 34). The FEA model (ref. 36) is aligned to observed surface temperatures and used to estimate peak temperatures, oscillations, and cooling rates; it is interpretive modeling rather than a derived prediction that is then verified by the same data. Refs. 34, 36, 32, and 40 include authors overlapping with the present paper, but they are published instrument calibrations and equations of state, not unverified premises used to force the conclusion. The paper's own caveats about possible nonthermal transitions, rapid cooling, and solidification from a possibly molten state are limitations on the thermodynamic interpretation of the bcc phase, not circularity in the structural assignment. No equation or parameter in the paper reduces to the claimed bcc observation by construction.

Assumptions & free parameters 3 free parameters · 7 assumptions · 0 invented entities

The central claim rests on a chain of standard experimental conversions and interpretive assumptions. The free-parameter count is small (temperature estimate and FEA inputs); no per-period or global fitting parameters are introduced to force the bcc identification. The axioms are mostly domain assumptions about pressure calibration, phase purity, and whether rapid-cooling/nonthermal effects preserve the equilibrium phase. The bcc phase itself is a known allotrope, not an invented entity.

free parameters (3)
  • SOP temperature estimate at bcc appearance = 4382±70 K (statistical), quoted as 4400(500) K
    Fit of Planck function to streak camera emission (Fig. S4); used to place bcc near melting and to set FEA temperature scale.
  • FEA thermal model inputs = k_Fe=50 W/m/K, k_KCl=20 W/m/K, 2 µm Fe, 1 µm KCl, 3 µm sigma
    Chosen from cited literature and geometry, not fitted to this run; they control the claim that peak temperatures exceed 6000 K.
  • Density regression slopes for hcp and bcc in Fig. 2 = Not quoted; small positive ΔV
    Linear fits to per-run densities used to infer positive volume change and a flat/positive Clapeyron slope; no uncertainties shown.
assumptions (7)
  • domain assumption The Dewaele et al. quasihydrostatic thermal equation of state of hcp-Fe [40] converts measured hcp-Fe volumes to pressure correctly at 4000-5000 K.
    All reported pressures (Table S2) and the 233-246 GPa range come from this EoS; an EoS error shifts the phase boundary.
  • domain assumption Coexisting bcc and hcp grains are at the same pressure, allowing the hcp-based pressure scale to be applied to the bcc phase.
    Pressure is derived only from hcp-Fe volumes; with steep temperature gradients, bcc grains could sit at different local pressure.
  • domain assumption The new reflection is not a contaminant or reaction product such as Fe3C, FeO, or a KCl-related phase.
    Excluded indirectly: structural dissimilarity and absence after quench. No elemental or chemical analysis is shown.
  • domain assumption The phase captured in the XRD snapshot at the minimum temperature of the pulse cycle represents the structure stable at the higher near-melting temperatures sampled by the preceding pulse.
    The text notes temperature can drop by 2000 K before probing and cooling rates reach ~10 K/ns; a metastable quench product is possible.
  • domain assumption The FEA thermal model (material properties in Table S1, 2D axisymmetric geometry) correctly estimates peak temperatures above 6000 K and the claim that part of the sample cools from the liquid.
    Peak temperatures are not measured directly; they come from the model.
  • ad hoc to paper The extremely high electronic excitation (10^15-10^16 W/cm2) does not produce a persistent nonthermal bcc phase; the observed bcc is thermally stabilized.
    The authors themselves flag this as an open question; the thermodynamic interpretation requires this assumption.
  • domain assumption A single observed reflection is sufficient to identify the phase as bcc, with fcc excluded by volume plausibility and the absence of the 200 reflection.
    Only one new line is observed; other high-symmetry or lower-symmetry structures with a coincident reflection are not exhaustively considered.

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Pith. "Pith review of Observation of Body-Centered Cubic Iron above 200 Gigapascals." pith.science (2026). https://pith.science/paper/XI2VLOL6

@misc{pith2026250515397,
  author       = {Pith},
  title        = {Pith review of: Observation of Body-Centered Cubic Iron above 200 Gigapascals},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/XI2VLOL6}},
  note         = {Machine review of arXiv:2505.15397}
}
read the original abstract

The crystallographic structure of iron under extreme conditions is a key benchmark for cutting-edge experimental and numerical methods. Moreover, it plays a crucial role in understanding planetary cores, as it significantly influences the interpretation of observational data and, consequently, insights into their internal structure and dynamics. However, even the structure of pure solid iron under the Earth's core conditions remains uncertain, with the commonly expected hexagonal close-packed structure energetically competitive with various cubic lattices. In this study, iron was compressed in a diamond anvil cell to above 200 GPa, and dynamically probed near the melting point using MHz frequency X-ray pulses from the European X-ray Free Electron Laser. The emergence of an additional diffraction line at high temperatures suggests the formation of an entropically stabilized bcc structure. Rapid heating and cooling cycles captured intermediate phases, offering new insights into iron's phase transformation paths. The appearance of the bcc phase near melting at extreme pressures challenges current understanding of the iron phase diagram under Earth's core conditions.

Figures

Figures reproduced from arXiv: 2505.15397 by the authors.

Figure 1
Figure 1. FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p006_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p007_3.png] view at source ↗
Figures from the paper (1 more)
Figure 4
Figure 4. Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p008_4.png]

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Works this paper leans on

61 extracted references · 58 canonical work pages

  1. [1]

    Hirose, S

    K. Hirose, S. Labrosse, and J. Hernlund, Composition and state of the core, Annual Review of Earth and Planetary Sciences 41, 657 (2013), https://doi.org/10.1146/annurev-earth-050212-124007

    doi:10.1146/annurev-earth-050212-124007 2013

  2. [2]

    R. Boehler, Melting temperature of the Earth’s mantle and core: Earth’s thermal structure, Annual Review of Earth and Planetary Sciences24, 15 (1996), https://doi.org/10.1146/annurev.earth.24.1.15

    work page doi:10.1146/annurev.earth.24.1.15 1996

  3. [3]

    Landeau, A

    M. Landeau, A. Fournier, H.-C. Nataf, D. C´ ebron, and N. Schaeffer, Sustaining Earth’s magnetic dynamo, Nature Reviews Earth & Environment3, 255 (2022)

    work page 2022

  4. [4]

    J. M. Brown and R. G. McQueen, Phase transitions, gr¨ uneisen parameter, and elasticity for shocked iron between 77 GPa and 400 GPa, Journal of Geophysical Research: Solid Earth91, 7485 (1986), https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/JB091iB07p07485

    work page doi:10.1029/jb091ib07p07485 1986

  5. [5]

    J. H. Nguyen and N. C. Holmes, Melting of iron at the physical conditions of the Earth’s core, Nature427, 339 (2004)

    work page 2004

  6. [6]

    Recentab initiosimulations augmented with machine learning have demonstrated the mechanical stability of the bcc structure of pure iron under Earth’s core conditions

    just below the melting point at high pressures. Recentab initiosimulations augmented with machine learning have demonstrated the mechanical stability of the bcc structure of pure iron under Earth’s core conditions. However, its thermodynamic stability compared to an hcp structure appears to be enhanced only in the presence of impurities [22]. Additional e...

    work page

  7. [7]

    Zhang, Y

    Y. Zhang, Y. Wang, Y. Huang, J. Wang, Z. Liang, L. Hao, Z. Gao, J. Li, Q. Wu, H. Zhang, Y. Liu, J. Sun, and J.-F. Lin, Collective motion in hcp-Fe at Earth’s inner core conditions, Proceedings of the National Academy of Sciences120, e2309952120 (2023), https://www.pnas.org/doi/pdf/10.1073/pnas.2309952120

    work page doi:10.1073/pnas.2309952120 2023

  8. [8]

    S. J. Turneaure, S. M. Sharma, and Y. M. Gupta, Crystal structure and melting of fe shock compressed to 273 GPa: In situ x-ray diffraction, Phys. Rev. Lett.125, 215702 (2020)

    work page 2020

Show all 61 references
  1. [9]

    Singh, R

    S. Singh, R. Briggs, M. G. Gorman, L. X. Benedict, C. J. Wu, S. Hamel, A. L. Coleman, F. Coppari, A. Fernandez-Pa˜ nella, C. McGuire, M. Sims, J. K. Wicks, J. H. Eggert, D. E. Fratanduono, and R. F. Smith, Structural study of hcp and liquid iron under shock compression up to 2...

    2023

  2. [10]

    White, B

    S. White, B. Kettle, J. Vorberger, C. L. S. Lewis, S. H. Glenzer, E. Gamboa, B. Nagler, F. Tavella, H. J. Lee, C. D. Murphy, D. O. Gericke, and D. Riley, Time-dependent effects in melting and phase change for laser-shocked iron, Phys. Rev. Res.2, 033366 (2020)

    2020

  3. [11]

    Y. Ping, F. Coppari, D. G. Hicks, B. Yaakobi, D. E. Fratanduono, S. Hamel, J. H. Eggert, J. R. Rygg, R. F. Smith, D. C. Swift, D. G. Braun, T. R. Boehly, and G. W. Collins, Solid iron compressed up to 560 GPa, Phys. Rev. Lett.111, 065501 (2013)

    2013

  4. [12]

    R. G. Kraus, R. J. Hemley, S. J. Ali, J. L. Belof, L. X. Benedict, J. Bernier, D. Braun, R. E. Cohen, G. W. Collins, F. Coppari, M. P. Desjarlais, D. Fratanduono, S. Hamel, A. Krygier, A. Lazicki, J. Mcnaney, M. Millot, P. C. Myint, M. G. Newman, J. R. Rygg, D. M. Sterbentz, S...

    2022

  5. [13]

    Tateno, K

    S. Tateno, K. Hirose, Y. Ohishi, and Y. Tatsumi, The structure of iron in Earth’s inner core, Science330, 359 (2010), http://science.sciencemag.org/content/330/6002/359.full.pdf

    2010

  6. [14]

    Anzellini, A

    S. Anzellini, A. Dewaele, M. Mezouar, P. Loubeyre, and G. Morard, Melting of iron at Earth’s inner core boundary based on fast x-ray diffraction, Science340, 464 (2013), http://science.sciencemag.org/content/340/6131/464.full.pdf

    2013

  7. [15]

    Stixrude and R

    L. Stixrude and R. E. Cohen, Constraints on the crystalline structure of the inner core: Me- chanical instability of bcc iron at high pressure, Geophysical Research Letters22, 125 (1995), https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/94GL02742

    1995 doi

  8. [16]

    Stixrude, Structure of Iron to 1 Gbar and 40 000 K, Physical Review Letters108, 1 (2012)

    L. Stixrude, Structure of Iron to 1 Gbar and 40 000 K, Physical Review Letters108, 1 (2012)

    2012

  9. [17]

    A. B. Belonoshko, T. Lukinov, J. Fu, J. Zhao, S. Davis, and S. I. Simak, Stabilization of body-centred cubic iron under inner-core conditions, Nature Geoscience10, 312 (2017)

    2017

  10. [18]

    Y. Sun, M. I. Mendelev, F. Zhang, X. Liu, B. Da, C.-Z. Wang, R. M. Wentzcovitch, and K.-M. Ho, Ab initio melting temperatures of bcc and hcp iron under the Earth’s inner core condition, Geophysical Research Letters50, e2022GL102447 (2023), e2022GL102447 2022GL102447, https://a...

    2023 doi

  11. [19]

    Vocadlo, D

    L. Vocadlo, D. Alfe, M. J. Gillan, I. G. Wood, J. P. Brodholt, and G. D. Price, Possible thermal and chemical stabilization of body-centred-cubic iron in the Earth’s core, Nature424, 536 (2003)

    2003

  12. [20]

    L. Zhao, V. Lordi, and A. Samanta, Melting point of iron at high pressure: An assessment of uncertainties and effect of electronic temperature, Applied Physics Letters124, 10.1063/5.0193357 (2024)

    2024 doi

  13. [21]

    A. B. Belonoshko, R. Ahuja, and B. Johansson, Stability of the body-centred-cubic phase of iron in the Earth’s inner core, Nature424, 1032 (2003)

    2003

  14. [22]

    A. B. Belonoshko, J. Fu, and G. Smirnov, Free energies of iron phases at high pressure and temperature: Molecular dynamics study, Physical Review B104, 1 (2021)

    2021

  15. [23]

    Li and S

    Z. Li and S. Scandolo, Competing phases of iron at earth’s core conditions from deep-learning-aided ab- initio simulations, Geophysical Research Letters51, e2024GL110357 (2024), e2024GL110357 2024GL110357, https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2024GL110357. 16

    2024 doi

  16. [24]

    Ghosh, S

    M. Ghosh, S. Zhang, L. Hu, and S. X. Hu, Cooperative diffusion in body-centered cubic iron in Earth and super-Earths’ inner core conditions, Journal of Physics Condensed Matter35, 10.1088/1361-648X/acba71 (2023)

    2023 doi

  17. [25]

    Balugani, J

    S. Balugani, J. A. Hernandez, N. S´ evelin-Radiguet, O. Mathon, V. Recoules, J. J. Kas, D. E. Eakins, H. Doyle, A. Ravasio, and R. Torchio, New Constraints on the Melting Temperature and Phase Stability of Shocked Iron up to 270 GPa Probed by Ultrafast X-Ray Absorption Spectro...

    2024

  18. [26]

    R. F. Smith, J. H. Eggert, D. C. Swift, J. Wang, T. S. Duffy, D. G. Braun, R. E. Rudd, D. B. Reisman, J. P. Davis, M. D. Knudson, and G. W. Collins, Time-dependence of the alpha to epsilon phase transformation in iron, Journal of Applied Physics114, 10.1063/1.4839655 (2013)

    2013 doi

  19. [27]

    M. G. Gorman, A. L. Coleman, R. Briggs, R. S. McWilliams, D. McGonegle, C. A. Bolme, A. E. Gleason, E. Galtier, H. J. Lee, E. Granados, M. ´Sliwa, C. Sanloup, S. Rothman, D. E. Fratanduono, R. F. Smith, G. W. Collins, J. H. Eggert, J. S. Wark, and M. I. McMahon, Femtosecond di...

    2018

  20. [28]

    Kuwayama, K

    Y. Kuwayama, K. Hirose, N. Sata, and Y. Ohishi, Phase relations of iron and iron-nickel alloys up to 300 GPa: Implications for composition and structure of the Earth’s inner core, Earth and Planetary Science Letters273, 379 (2008)

    2008

  21. [29]

    Konˆ opkov´ a, W

    Z. Konˆ opkov´ a, W. Morgenroth, R. Husband, N. Giordano, A. Pakhomova, O. Gutowski, M. Wendt, K. Glazyrin, A. Ehnes, J. T. Delitz, A. F. Goncharov, V. B. Prakapenka, and H.-P. Liermann, Laser heating system at the extreme conditions beamline, P02.2, PETRA III, Journal of Sync...

    2021

  22. [30]

    Sinmyo, K

    R. Sinmyo, K. Hirose, and Y. Ohishi, Melting curve of iron to 290 GPa determined in a resistance-heated diamond-anvil cell, Earth and Planetary Science Letters510, 45 (2019)

    2019

  23. [31]

    Aprilis, I

    G. Aprilis, I. Kantor, I. Kupenko, V. Cerantola, A. Pakhomova, I. E. Collings, R. Torchio, T. Fedotenko, S. Chariton, M. Bykov, E. Bykova, E. Koemets, D. M. Vasiukov, C. McCammon, L. Dubrovinsky, and N. Dubrovinskaia, Comparative study of the influence of pulsed and continuous...

    2019 doi

  24. [32]

    Morard, S

    G. Morard, S. Boccato, A. D. Rosa, S. Anzellini, F. Miozzi, L. Henry, G. Garbarino, M. Mezouar, M. Harmand, F. Guyot, E. Boulard, I. Kantor, T. Irifune, and R. Torchio, Solving controversies on the iron phase diagram under high pressure, Geophysical Research Letters45, 11,074 ...

    2018 doi

  25. [33]

    H. P. Liermann, Z. Konˆ opkov´ a, K. Appel, C. Prescher, A. Schropp, V. Cerantola, R. J. Husband, J. D. McHardy, M. I. McMahon, R. S. McWilliams, C. M. P´ epin, J. Mainberger, M. Roeper, A. Bergh¨ auser, H. Damker, P. Talkovski, M. Foese, N. Kujala, O. B. Ball, M. A. Baron, R....

    2021

  26. [34]

    Zastrau, K

    U. Zastrau, K. Appel, C. Baehtz, O. Baehr, L. Batchelor, A. Bergh¨ auser, M. Banjafar, E. Brambrink, V. Cerantola, T. E. Cowan, H. Damker, S. Dietrich, S. Di Dio Cafiso, J. Dreyer, H.-O. Engel, T. Feldmann, S. Findeisen, M. Foese, D. Fulla- Marsa, S. G¨ ode, M. Hassan, J. Haus...

    2021

  27. [35]

    O. B. Ball, C. Prescher, K. Appel, C. Baehtz, M. A. Baron, R. Briggs, V. Cerantola, J. Chantel, S. Chariton, A. L. Coleman, H. Cynn, H. Damker, D. Dattelbaum, L. E. Dresselhaus-Marais, J. H. Eggert, L. Ehm, W. J. Evans, G. Fi- quet, M. Frost, K. Glazyrin, A. F. Goncharov, R. J...

    2023

  28. [36]

    A. S. Mikhaylushkin, S. I. Simak, L. Dubrovinsky, N. Dubrovinskaia, B. Johansson, and I. A. Abrikosov, Pure iron compressed and heated to extreme conditions, Phys. Rev. Lett.99, 165505 (2007)

    2007

  29. [37]

    Meza-Galvez, N

    J. Meza-Galvez, N. Gomez-Perez, A. S. Marshall, A. L. Coleman, K. Appel, H. P. Liermann, M. I. McMahon, Z. Konˆ opkov´ a, and R. S. McWilliams, Thermomechanical response of thickly tamped targets and diamond anvil cells under pulsed hard x-ray irradiation, Journal of Applied P...

    2020 doi

  30. [38]

    J. N. Zhou, Y. F. Guo, J. Y. Ren, and X. Z. Tang, The mechanism of hcp-bcc phase transformation in Mg single crystal under high pressure, Scripta Materialia236, 115670 (2023). 17

    2023

  31. [39]

    Sadigh, L

    B. Sadigh, L. Zepeda-Ruiz, and J. L. Belof, Metastable-solid phase diagrams derived from polymorphic solidification kinetics, Proceedings of the National Academy of Sciences of the United States of America118, 10.1073/pnas.2017809118 (2021)

    2021 doi

  32. [40]

    Azadi, J

    S. Azadi, J. S. Wark, and S. M. Vinko, Nonthermal solid-solid phase transition in ferromagnetic iron, PHYSICAL REVIEW B214434, 1 (2024)

    2024

  33. [41]

    Dewaele, P

    A. Dewaele, P. Loubeyre, F. Occelli, M. Mezouar, P. I. Dorogokupets, and M. Torrent, Quasihydrostatic equation of state of iron above 2 Mbar, Phys. Rev. Lett.97, 215504 (2006)

    2006

  34. [42]

    W. A. Bassett and M. S. Weathers, Stability of the body-centered cubic phase of iron: A thermodynamic analysis, Journal of Geophysical Research: Solid Earth95, 21709 (1990), https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/JB095iB13p21709

    1990 doi

  35. [43]

    Komabayashi and Y

    T. Komabayashi and Y. Fei, Internally consistent thermodynamic database for iron to the Earth’s core conditions, J. Geophys. Res.115, B03202 (2010)

    2010

  36. [44]

    L. V. Pourovskii, T. Miyake, S. I. Simak, A. V. Ruban, L. Dubrovinsky, and I. A. Abrikosov, Electronic properties and magnetism of iron at the Earth’s inner core conditions, Phys. Rev. B87, 115130 (2013)

    2013

  37. [45]

    Alf` e, M

    D. Alf` e, M. J. Gillan, and G. D. Price, Constraints on the composition of the Earth’s core from ab initio calculations, Nature405, 172 (2000)

    2000

  38. [46]

    Y. Li, L. Voˇ cadlo, D. Alf` e, and J. Brodholt, Carbon partitioning between the Earth’s in- ner and outer core, Journal of Geophysical Research: Solid Earth124, 12812 (2019), https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2019JB018789

    2019 doi

  39. [47]

    Ozawa, K

    H. Ozawa, K. Hirose, K. Yonemitsu, and Y. Ohishi, High-pressure melting experiments on Fe–Si alloys and implications for silicon as a light element in the core, Earth and Planetary Science Letters456, 47 (2016)

    2016

  40. [48]

    Miozzi, G

    F. Miozzi, G. Morard, D. Antonangeli, M. Baron, S. Boccato, A. Pakhomova, G. Garbarino, M. Mezouar, and G. Fiquet, Eutectic melting of Fe-3 at Si-4 at C up to 200 GPa and implications for the Earth’s core, Earth and Planetary Science Letters544, 116382 (2020)

    2020

  41. [49]

    Tagawa, G

    S. Tagawa, G. Helffrich, K. Hirose, and Y. Ohishi, High-pressure melting curve of FeH: Implications for eutectic melting be- tween Fe and non-magnetic FeH, Journal of Geophysical Research: Solid Earth127, e2022JB024365 (2022), e2022JB024365 2022JB024365, https://agupubs.online...

    2022 doi

  42. [50]

    Edmund, D

    E. Edmund, D. Antonangeli, F. Decremps, F. Miozzi, G. Morard, E. Boulard, A. N. Clark, S. Ayrinhac, M. Gauthier, M. Morand, and M. Mezouar, Velocity-density systematics of Fe-5wt%Si: Constraints on si con- tent in the Earth’s inner core, Journal of Geophysical Research: Solid ...

    2019 doi

  43. [51]

    Huang, L

    H. Huang, L. Fan, X. Liu, F. Xu, Y. Wu, G. Yang, C. Leng, Q. Wang, J. Weng, X. Wang, L. Cai, and Y. Fei, Inner core composition paradox revealed by sound velocities of Fe and Fe-Si alloy, Nature Communications13, 616 (2022)

    2022

  44. [52]

    Martorell, I

    B. Martorell, I. G. Wood, J. Brodholt, and L. Voˇ cadlo, The elastic properties of hcp-Fe 1−xSix at Earth’s inner-core conditions, Earth and Planetary Science Letters451, 89 (2016)

    2016

  45. [53]

    Y. He, S. Sun, D. Y. Kim, B. G. Jang, H. Li, and H.-k. Mao, Superionic iron alloys and their seismic velocities in Earth’s inner core, Nature602, 258 (2022)

    2022

  46. [54]

    Lythgoe, A

    K. Lythgoe, A. Deuss, J. Rudge, and J. Neufeld, Earth s inner core: Innermost inner core or hemispherical variations?, Earth and Planetary Science Letters385, 181 (2014)

    2014

  47. [55]

    D. A. Frost, M. Lasbleis, B. Chandler, and B. Romanowicz, Dynamic history of the inner core constrained by seismic anisotropy, Nature Geoscience14, 531 (2021)

    2021

  48. [56]

    Costa de Lima, H

    T. Costa de Lima, H. Tkalˇ ci´ c, and L. Waszek, A new probe into the innermost inner core anisotropy via the global coda-correlation wavefield, Journal of Geophysical Research: Solid Earth127, e2021JB023540 (2022), e2021JB023540 2021JB023540, https://agupubs.onlinelibrary.wil...

    2022 doi

  49. [57]

    Tkalˇ ci´ c, A

    H. Tkalˇ ci´ c, A. B. Belonoshko, J. B. Muir, M. Mattesini, L. Moresi, and L. Waszek, Imaging the top of the Earth’s inner core: a present-day flow model, Scientific Reports14, 8999 (2024)

    2024

  50. [58]

    Mattesini, A

    M. Mattesini, A. B. Belonoshko, H. Tkalˇ ci´ c, E. Buforn, A. Ud ´ ıas, and R. Ahuja, Candy wrapper for the Earth’s inner core, Scientific Reports3, 2096 (2013)

    2013

  51. [59]

    Lincot, S

    A. Lincot, S. Merkel, and P. Cardin, Is inner core seismic anisotropy a marker for plastic flow of cubic iron?, Geophysical Research Letters42, 1326 (2015), https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2014GL062862

    2015 doi

  52. [60]

    Akahama and H

    Y. Akahama and H. Kawamura, Pressure calibration of diamond anvil raman gauge to 310 GPa, Journal of Applied Physics 100, 043516 (2006), https://doi.org/10.1063/1.2335683

    2006 doi

  53. [61]

    Maltezopoulos, F

    T. Maltezopoulos, F. Dietrich, W. Freund, U. F. Jastrow, A. Koch, J. Laksman, J. Liu, M. Planas, A. A. Sorokin, K. Tiedtke, and J. Gr¨ unert, Operation of X-ray gas monitors at the European XFEL, Journal of Synchrotron Radiation 26, 1045 (2019)

    2019

Pith tools

Reviewed August 7, 2026 · model on record in the stance chip above.