_version_ 1866918028917080064
author Konopkova, Zuzana
Edmund, Eric
Ball, Orianna B
Dewaele, Agnes
Ginestet, Helene
Husband, Rachel J
Jaisle, Nicolas
Strohm, Cornelius
Anae, Madden S
Antonangeli, Daniele
Appel, Karen
Baron, Marzena
Boccato, Silvia
Buakor, Khachiwan
Chantel, Julien
Cynn, Hyunchae
Dwivedi, Anand P
Ehm, Lars
Glazyrin, Konstantin
Graafsma, Heinz
Koemets, Egor
Laurus, Torsten
Marquardt, Hauke
Massani, Bernhard
McHardy, James D
McMahon, Malcolm I
Prakapenka, Vitali
Sztuk-Dambietz, Jolanta
Tang, Minxue
Xie, Tianqi
Younes, Zena
Zastrau, Ulf
Goncharov, Alexander F
Prescher, Clemens
McWilliams, Ryan S
Morard, Guillaume
Merkel, Sebastien
author_facet Konopkova, Zuzana
Edmund, Eric
Ball, Orianna B
Dewaele, Agnes
Ginestet, Helene
Husband, Rachel J
Jaisle, Nicolas
Strohm, Cornelius
Anae, Madden S
Antonangeli, Daniele
Appel, Karen
Baron, Marzena
Boccato, Silvia
Buakor, Khachiwan
Chantel, Julien
Cynn, Hyunchae
Dwivedi, Anand P
Ehm, Lars
Glazyrin, Konstantin
Graafsma, Heinz
Koemets, Egor
Laurus, Torsten
Marquardt, Hauke
Massani, Bernhard
McHardy, James D
McMahon, Malcolm I
Prakapenka, Vitali
Sztuk-Dambietz, Jolanta
Tang, Minxue
Xie, Tianqi
Younes, Zena
Zastrau, Ulf
Goncharov, Alexander F
Prescher, Clemens
McWilliams, Ryan S
Morard, Guillaume
Merkel, Sebastien
contents 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.
format Preprint
id arxiv_https___arxiv_org_abs_2505_15397
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Observation of Body-Centered Cubic Iron above 200 Gigapascals
Konopkova, Zuzana
Edmund, Eric
Ball, Orianna B
Dewaele, Agnes
Ginestet, Helene
Husband, Rachel J
Jaisle, Nicolas
Strohm, Cornelius
Anae, Madden S
Antonangeli, Daniele
Appel, Karen
Baron, Marzena
Boccato, Silvia
Buakor, Khachiwan
Chantel, Julien
Cynn, Hyunchae
Dwivedi, Anand P
Ehm, Lars
Glazyrin, Konstantin
Graafsma, Heinz
Koemets, Egor
Laurus, Torsten
Marquardt, Hauke
Massani, Bernhard
McHardy, James D
McMahon, Malcolm I
Prakapenka, Vitali
Sztuk-Dambietz, Jolanta
Tang, Minxue
Xie, Tianqi
Younes, Zena
Zastrau, Ulf
Goncharov, Alexander F
Prescher, Clemens
McWilliams, Ryan S
Morard, Guillaume
Merkel, Sebastien
Materials Science
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.
title Observation of Body-Centered Cubic Iron above 200 Gigapascals
topic Materials Science
url https://arxiv.org/abs/2505.15397