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In situ x-ray diffraction of the α−ɛ phase transition in iron at intermediate strain rates

Minxue Tang1,2,*,†, Rachel Husband1, Zuzana Konôpková3, Karen Appel3, Erik Brambrink3, Khachiwan Buakor3, Victorien Bouffetier3, Jolanta Sztuk-Dambietz3, Heinz Graafsma1 et al.

Torsten Laurus1, Hauke Höppner3, Alexander Pelka3, Sheng-Nian Luo2, and Cornelius Strohm1

  • *Contact author: minxue.tang@xfel.eu
  • †Present address: European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany.
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Phys. Rev. Research 8, 013135 – Published 6 February, 2026

DOI: https://doi.org/10.1103/b3sn-8y4t

Abstract

The α(bcc)-ɛ(hcp) phase transition in polycrystalline Fe has been investigated under fast quasihydrostatic compression using piezoelectric actuator driven dynamic diamond anvil cells. X-ray diffraction data from Fe under intermediate strain rate compression were collected at megahertz repetition rates. Our results demonstrate, for the first time, the full evolution of the α−ɛ phase transition in powder and foil samples at strain rates of ∼102s−1. Under fast compression, the majority of the α phase transforms to ɛ-Fe in a timescale of tens of microseconds, with a corresponding coexistence pressure of ∼2GPa. The observed onset phase transition pressure of 13.4–14.4 GPa is in good agreement with the results of previous quasihydrostatic compression studies, suggesting that the transition is not influenced by compression rates up to ∼80TPas−1.

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References (75)

  1. D. Milathianaki, et al., Femtosecond visualization of lattice dynamics in shock-compressed matter, Science 342, 220 (2013).
  2. C. E. Wehrenberg, et al., In situ X-ray diffraction measurement of shock-wave-driven twinning and lattice dynamics, Nature (London) 550, 496 (2017).
  3. M. Mo, et al., Ultrafast visualization of incipient plasticity in dynamically compressed matter, Nat. Commun. 13, 1055 (2022).
  4. S. M. Sharma, et al., Structural transformation and melting in gold shock compressed to 355 GPa, Phys. Rev. Lett. 123, 045702 (2019).
  5. S. Chen, et al., Capture deformation twinning in mg during shock compression with ultrafast synchrotron x-ray diffraction, Phys. Rev. Lett. 123, 255501 (2019).
  6. L. Lu, T. Sun, K. Fezzaa, X. L. Gong, and S. N. Luo, Simultaneous multiscale measurements on dynamic deformation of a magnesium alloy with synchrotron x-ray imaging and diffraction, Mater. Sci. Eng.: A 701, 143 (2017).
  7. F. Zhang, et al., Polymorphism in a high-entropy alloy, Nat. Commun. 8, 15687 (2017).
  8. S. Eswarappa Prameela, T. M. Pollock, D. Raabe, M. A. Meyers, A. Aitkaliyeva, K.-L. Chintersingh, Z. C. Cordero, and L. Graham-Brady, Materials for extreme environments, Nat. Rev. Mater. 8, 81 (2022).
  9. R. J. Hemley, G. W. Crabtree, and M. V. Buchanan, Materials in extreme environments, Phys. Today 62, 32 (2009).
  10. G. Shen and H. K. Mao, High-pressure studies with x-rays using diamond anvil cells, Rep. Prog. Phys. 80, 016101 (2017).
  11. A. Jayaraman, Diamond anvil cell and high-pressure physical investigations, Rev. Mod. Phys. 55, 65 (1983).
  12. R. Letoullec, J. P. Pinceaux, and P. Loubeyre, The membrane diamond anvil cell: A new device for generating continuous pressure and temperature variations, High Pressure Res. 1, 77 (1988).
  13. D. Fan, J. W. Huang, X. L. Zeng, Y. Li, C. E J., J. Y. Huang, T. Sun, K. Fezzaa, Z. Wang, and S. N. Luo, Simultaneous, single-pulse, synchrotron x-ray imaging and diffraction under gas gun loading, Rev. Sci. Instrum. 87, 053903 (2016).
  14. G. R. Fowles, G. E. Duvall, J. Asay, P. Bellamy, F. Feistmann, D. Grady, T. Michaels, and R. Mitchell, Gas gun for impact studies, Rev. Sci. Instrum. 41, 984 (1970).
  15. S. J. Turneaure and Y. M. Gupta, Real-time x-ray diffraction at the impact surface of shocked crystals, J. Appl. Phys. 111, 026101 (2012).
  16. X. Wang, et al., The laser shock station in the dynamic compression sector. I, Rev. Sci. Instrum. 90, 053901 (2019).
  17. T. P. Remington, B. A. Remington, E. N. Hahn, and M. A. Meyers, Deformation and failure in extreme regimes by high-energy pulsed lasers: A review, Mater. Sci. Eng.: A 688, 429 (2017).
  18. P. Peyre and R. Fabbro, Laser shock processing: A review of the physics and applications, Opt. Quantum Electron. 27, 1213 (1995).
  19. H.-S. Park, et al., Techniques for studying materials under extreme states of high energy density compression, Phys. Plasmas 28, 060901 (2021).
  20. R. F. Smith, J. H. Eggert, M. D. Saculla, A. F. Jankowski, M. Bastea, D. G. Hicks, and G. W. Collins, Ultrafast dynamic compression technique to study the kinetics of phase transformations in bismuth, Phys. Rev. Lett. 101, 065701 (2008).
  21. C. M. Pépin, A. Sollier, A. Marizy, F. Occelli, M. Sander, R. Torchio, and P. Loubeyre, Kinetics and structural changes in dynamically compressed bismuth, Phys. Rev. B 100, 060101(R) (2019).
  22. Y. K. Vohra and A. L. Ruoff, Static compression of metals Mo, Pb, and Pt to 272 GPa: Comparison with shock data, Phys. Rev. B 42, 8651 (1990).
  23. J. Y. Huang, J. C. E., J. W. Huang, T. Sun, K. Fezzaa, S. L. Xu, and S. N. Luo, Dynamic deformation and fracture of single crystal silicon: Fracture modes, damage laws, and anisotropy, Acta Mater. 114, 136 (2016).
  24. J. Yan, X. Liu, F. A. Gorelli, H. Xu, H. Zhang, H. Hu, E. Gregoryanz, and P. Dalladay-Simpson, Compression rate of dynamic diamond anvil cells from room temperature to 10 K, Rev. Sci. Instrum. 93, 063901 (2022).
  25. Z. Jenei, et al., New dynamic diamond anvil cells for tera-pascal per second fast compression x-ray diffraction experiments, Rev. Sci. Instrum. 90, 065114 (2019).
  26. R. J. Husband, et al., A MHz X-ray diffraction set-up for dynamic compression experiments in the diamond anvil cell, J. Synchrotron. Radat. 30, 671 (2023).
  27. T. Takahashi and W. A. Bassett, High-pressure polymorph of iron, Science 145, 483 (1964).
  28. H. Mao, W. A. Bassett, and T. Takahashi, Effect of pressure on crystal structure and lattice parameters of iron up to 300 kbar, J. Appl. Phys. 38, 272 (1967).
  29. W. A. Bassett and E. Huang, Mechanism of the body-centered cubic—hexagonal close-packed phase transition in iron, Science 238, 780 (1987).
  30. E. Huang, W. A. Bassett, and P. Tao, Study of bcc-hcp iron phase transition by synchrotron radiation, in Geophysical Monograph Series, edited by M. H. Manghnani and Y. Syono (American Geophysical Union, Washington, DC, 1987), Vol. 39, pp. 165–172.
  31. M. H. Manghnani, L. C. Ming, and N. Nakagiri, Investigation of the α-Fe ⇌ ɛ-Fe phase Transition by Synchrotron Radiation, in Geophysical Monograph Series, edited by M. H. Manghnani and Y. Syono (American Geophysical Union, Washington, DC, 1987), Vol. 39, pp. 155–163.
  32. R. Boehler, N. Von Bargen, and A. Chopelas, Melting, thermal expansion, and phase transitions of iron at high pressures, J. Geophys. Res. 95, 21731 (1990).
  33. R. D. Taylor, M. P. Pasternak, and R. Jeanloz, Hysteresis in the high pressure transformation of bcc- to hcp-iron, J. Appl. Phys. 69, 6126 (1991).
  34. F. M. Wang and R. Ingalls, Iron bcc-hcp transition: Local structure from x-ray-absorption fine structure, Phys. Rev. B 57, 5647 (1998).
  35. S. Merkel, H.-R. Wenk, P. Gillet, H. Mao, and R. J. Hemley, Deformation of polycrystalline iron up to 30 GPa and 1000 K, Phys. Earth Planet. Inter. 145, 239 (2004).
  36. O. Mathon, F. Baudelet, J. P. Itié, A. Polian, M. d’Astuto, J. C. Chervin, and S. Pascarelli, Dynamics of the magnetic and structural α−ɛ phase transition in iron, Phys. Rev. Lett. 93, 255503 (2004).
  37. 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).
  38. A. K. Singh, A. Jain, H. P. Liermann, and S. K. Saxena, Strength of iron under pressure up to 55GPa from X-ray diffraction line-width analysis, J. Phys. Chem. Solids 67, 2197 (2006).
  39. Z. Konôpková, A. Rothkirch, A. K. Singh, S. Speziale, and H.-P. Liermann, In situ x-ray diffraction of fast compressed iron: Analysis of strains and stress under non-hydrostatic pressure, Phys. Rev. B 91, 144101 (2015).
  40. A. Dewaele, C. Denoual, S. Anzellini, F. Occelli, M. Mezouar, P. Cordier, S. Merkel, M. Véron, and E. Rausch, Mechanism of the α−ɛ phase transformation in iron, Phys. Rev. B 91, 174105 (2015).
  41. S. Merkel, A. Lincot, and S. Petitgirard, Microstructural effects and mechanism of bcc-hcp-bcc transformations in polycrystalline iron, Phys. Rev. B 102, 104103 (2020).
  42. R. Fréville, A. Dewaele, N. Bruzy, V. Svitlyk, and G. Garbarino, Comparison between mechanisms and microstructures of α−γ, γ−ɛ, and α−ɛ−α phase transitions in iron, Phys. Rev. B 107, 104105 (2023).
  43. M. Ricks, A. E. Gleason, F. Miozzi, H. Yang, S. Chariton, V. B. Prakapenka, S. V. Sinogeikin, R. L. Sandberg, W. L. Mao, and S. Pandolfi, Phase transition kinetics revealed by in situ x-ray diffraction in laser-heated dynamic diamond anvil cells, Phys. Rev. Res. 6, 013316 (2024).
  44. D. Bancroft, E. L. Peterson, and S. Minshall, Polymorphism of iron at high pressure, J. Appl. Phys. 27, 291 (1956).
  45. J. C. Boettger and D. C. Wallace, Metastability and dynamics of the shock-induced phase transition in iron, Phys. Rev. B 55, 2840 (1997).
  46. J. Hawreliak, et al., Analysis of the x-ray diffraction signal for the α-ε transition in shock-compressed iron: Simulation and experiment, Phys. Rev. B 74, 184107 (2006).
  47. J. C. Crowhurst, B. W. Reed, M. R. Armstrong, H. B. Radousky, J. A. Carter, D. C. Swift, J. M. Zaug, R. W. Minich, N. E. Teslich, and M. Kumar, The α→ ε phase transition in iron at strain rates up to ∼109s−1, J. Appl. Phys. 115, 113506 (2014).
  48. J. A. Hawreliak, et al., In situ x-ray diffraction measurements of the c/a ratio in the high-pressure ɛ phase of shock-compressed polycrystalline iron, Phys. Rev. B 83, 144114 (2011).
  49. R. F. Smith, et al., Time-dependence of the alpha to epsilon phase transformation in iron, J. Appl. Phys. 114, 223507 (2013).
  50. H. Hwang, et al., Subnanosecond phase transition dynamics in laser-shocked iron, Sci. Adv. 6, eaaz5132 (2020).
  51. D. H. Kalantar, et al., Direct observation of the α−ɛ transition in shock-compressed iron via nanosecond X-ray diffraction, Phys. Rev. Lett. 95, 075502 (2005).
  52. J. P. Rueff, M. Krisch, Y. Q. Cai, A. Kaprolat, M. Hanfland, M. Lorenzen, C. Masciovecchio, R. Verbeni, and F. Sette, Magnetic and structural α−ɛ phase transition in Fe monitored by x-ray emission spectroscopy, Phys. Rev. B 60, 14510 (1999).
  53. See Supplemental Material at http://link.aps.org/supplemental/10.1103/b3sn-8y4t for additional figures and tables and detailed supporting analyses.
  54. T. Komabayashi, Y. Fei, Y. Meng, and V. Prakapenka, In-situ X-ray diffraction measurements of the γ−ɛ transition boundary of iron in an internally-heated diamond anvil cell, Earth Planet. Sci. Lett. 282, 252 (2009).
  55. C. Plückthun, Investigating the effect of the compression rate on the kinetic response of diamond anvil cell experiments, Ph.D. thesis, Universität Rostock, 2021, doi: 10.18453/ROSDOK_ID00003440.
  56. B. J. Jensen, G. T. Gray, and R. S. Hixson, Direct measurements of the α-ε transition stress and kinetics for shocked iron, J. Appl. Phys. 105, 103502 (2009).
  57. N. Amadou, et al., Direct laser-driven ramp compression studies of iron: A first step toward the reproduction of planetary core conditions, High Energy Density Phys. 9, 243 (2013).
  58. N. Amadou, et al., Kinetics of the iron α−ɛ phase transition at high-strain rates: Experiment and model, Phys. Rev. B 93, 214108 (2016).
  59. U. Zastrau, et al., The high energy density scientific instrument at the european XFEL, J. Synchrotron Radat. 28, 1393 (2021).
  60. B. Henrich, et al., The adaptive gain integrating pixel detector AGIPD a detector for the European XFEL, Nucl. Instrum. Methods Phys. Res. Sect. A 633, S11 (2011).
  61. J. Meza-Galvez, N. Gomez-Perez, A. S. Marshall, A. L. Coleman, K. Appel, H. P. Liermann, M. I. McMahon, Z. Konôpková, and R. S. McWilliams, Thermomechanical response of thickly tamped targets and diamond anvil cells under pulsed hard x-ray irradiation, J. Appl. Phys. 127, 195902 (2020).
  62. J. M. Kaa, et al., Structural and electron spin state changes in an x-ray heated iron carbonate system at the Earth’s lower mantle pressures, Phys. Rev. Res. 4, 033042 (2022).
  63. J. M. Kaa, et al., A von Hámos spectrometer for diamond anvil cell experiments at the High Energy Density Instrument of the European X-ray Free-Electron Laser, J. Synchrotron Radat. 30, 822 (2023).
  64. C. Prescher and V. B. Prakapenka, DIOPTAS: A program for reduction of two-dimensional X-ray diffraction data and data exploration, High Pressure Res. 35, 223 (2015).
  65. J. Zhang and F. Guyot, Thermal equation of state of iron and Fe0.91Si0.09, Phys. Chem. Miner. 26, 206 (1999).
  66. C. A. Rotter and C. S. Smith, Ultrasonic equation of state of iron: I. Low pressure, room temperature, J. Phys. Chem. Solids 27, 267 (1966).
  67. S. Klotz, J.-C. Chervin, P. Munsch, and G. Le Marchand, Hydrostatic limits of 11 pressure transmitting media, J. Phys. D: Appl. Phys. 42, 075413 (2009).
  68. J.-L. Shao, P. Wang, F.-G. Zhang, and A.-M. He, Hcp/fcc nucleation in bcc iron under different anisotropic compressions at high strain rate: Molecular dynamics study, Sci. Rep. 8, 7650 (2018).
  69. R. J. Husband, E. F. O’Bannon, H.-P. Liermann, M. J. Lipp, A. S. J. Méndez, Z. Konôpková, E. E. McBride, W. J. Evans, and Z. Jenei, Compression-rate dependence of pressure-induced phase transitions in Bi, Sci. Rep. 11, 14859 (2021).
  70. V. V. Dremov, Equation of state and phase diagram of iron, in AIP Conference Proceedings (AIP, Atlanta, Georgia, 2002), Vol. 620, pp. 87–90.
  71. D. Andrault, G. Fiquet, M. Kunz, F. Visocekas, and D. Häusermann, The orthorhombic structure of iron: An in situ study at high-temperature and high-pressure, Science 278, 831 (1997).
  72. G. I. Kanel, S. V. Razorenov, and V. E. Fortov, Shock-wave compression and tension of solids at elevated temperatures: Superheated crystal states, pre-melting, and anomalous growth of the yield strength, J. Phys.: Condens. Matter 16, S1007 (2004).
  73. P. C. Johnson, B. A. Stein, and R. S. Davis, Temperature dependence of shock-induced phase transformations in iron, J. Appl. Phys. 33, 557 (1962).
  74. J. Li, Q. Wu, T. Xue, H. Geng, J. Yu, K. Jin, J. Li, Y. Tan, and F. Xi, The α−γ−ɛ triple point and phase boundaries of iron under shock compression, J. Appl. Phys. 122, 025901 (2017).
  75. https://doi.org/10.22003/XFEL.EU-DATA-003246-00

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Phys. Rev. Research 8, 013135– Published 6 February, 2026
  • Received 29 September 2025
  • Accepted 17 December 2025
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