Observation of body-centered cubic iron above 200 gigapascals

@article{konopkova2026observation,
  title = {{Observation of body-centered cubic iron above 200 gigapascals}},
  author = {Zuzana Konôpková and Eric Edmund and Orianna B. Ball and Agnès Dewaele and Hélène Ginestet and Rachel J. Husband and Nicolas Jaisle and C. Strohm and Madden S. Anae and Daniele Antonangeli and Karen Appel and Marzena Anna Baron and Silvia Boccato and Khachiwan Buakor and Julien Chantel and Hyunchae Cynn and Anand Dwivedi and Lars Ehm and Konstantin V. Glazyrin and Heinz Graafsma and Egor Koemets and Torsten Laurus and Hauke Marquardt and Bernhard Massani and James D. McHardy and Malcolm I. McMahon and Vitali B. Prakapenka and J. Sztuk-Dambietz and Minxue Tang and Tianqi Xie and Zena Younes and U. Zastrau and Alexander F. Goncharov and Clemens Prescher and R. S. McWilliams and G. Morard and Sébastien Merkel},
  journal = {Physical review. B./Physical review. B},
  year = {2026},
  month = jul,
  doi = {10.1103/kxnf-6c5y},
  url = {https://doi.org/10.1103/kxnf-6c5y},
  note = {CC BY},
}

TY  - JOUR
TI  - Observation of body-centered cubic iron above 200 gigapascals
AU  - Zuzana Konôpková
AU  - Eric Edmund
AU  - Orianna B. Ball
AU  - Agnès Dewaele
AU  - Hélène Ginestet
AU  - Rachel J. Husband
AU  - Nicolas Jaisle
AU  - C. Strohm
AU  - Madden S. Anae
AU  - Daniele Antonangeli
AU  - Karen Appel
AU  - Marzena Anna Baron
AU  - Silvia Boccato
AU  - Khachiwan Buakor
AU  - Julien Chantel
AU  - Hyunchae Cynn
AU  - Anand Dwivedi
AU  - Lars Ehm
AU  - Konstantin V. Glazyrin
AU  - Heinz Graafsma
AU  - Egor Koemets
AU  - Torsten Laurus
AU  - Hauke Marquardt
AU  - Bernhard Massani
AU  - James D. McHardy
AU  - Malcolm I. McMahon
AU  - Vitali B. Prakapenka
AU  - J. Sztuk-Dambietz
AU  - Minxue Tang
AU  - Tianqi Xie
AU  - Zena Younes
AU  - U. Zastrau
AU  - Alexander F. Goncharov
AU  - Clemens Prescher
AU  - R. S. McWilliams
AU  - G. Morard
AU  - Sébastien Merkel
PY  - 2026
DA  - 2026/07/15
JO  - Physical review. B./Physical review. B
DO  - 10.1103/kxnf-6c5y
UR  - https://doi.org/10.1103/kxnf-6c5y
AB  - The crystallographic structure of iron under extreme conditions is a key benchmark for state-of-the-art experimental and computational methods. Moreover, it plays a crucial role in our understanding of planetary cores, as it strongly influences the interpretation of observational data and, consequently, our knowledge of their internal structure and dynamics. However, even the crystal structure of pure solid iron under Earth's core conditions remains uncertain, with the commonly expected hexagonal close-packed phase being energetically competitive with several cubic structures. In this study, iron was compressed in a diamond anvil cell to pressures exceeding 200 GPa and dynamically probed near its melting point using MHz-frequency x-ray pulses from the European X-ray Free-Electron Laser. In the pressure range between 120 and 160 GPa, the high temporal resolution of the structural snapshots at elevated temperatures revealed the face-centered cubic phase, extending its observed stability to higher pressures than previously reported. Brief appearances of intermediate or disordered phases, including body-centered cubic (bcc) and stacking-faulted structures, were also observed. Above 230 GPa, new diffraction reflections emerged at high temperatures and are interpreted as evidence for the nucleation of a previously unreported phase, which subsequently evolved into a powderlike diffraction pattern characteristic of the bcc structure. The unprecedented time resolution of the structural data acquired during rapid heating and cooling cycles provides insights into the kinetics and mechanisms of phase transformations in iron at these extreme pressures.
SN  - 2469-9950
SN  - 2469-9969
SN  - 2469-9977
ER  -