To investigate the states of materials in detail, physical ddproperty measurements using microscopic probes are indispensable. Although microscopic measurements under the pulsed ultrahigh magnetic fields are highly challenging, they are essential for advancing high magnetic-field science. Recently, Ikeda group (the University of Electro-Communications) has developed a single-shot X-ray diffraction (XRD) at SACLA by combining an X-ray free-electron laser with the portable pulsed high-field generator PINK-02. CUrrently, powder XRD experiments up to 110 T down to 5 K are available [A].

　Using this technique, we investigated changes in lattice symmetry across the field-induced phase transition of the breathing-pyrochlore magnet CuGaCr₄S₈. CuGaCr₄S₈ undergoes a structural transition below 31 K, developing an orthorhombic distortion and an incommensurate helical magnetic order [B]. Upon applying a magnetic field, a metamagnetic transition occurs at 40 T, followed by a 1/2 magnetization plateau [C]. Focusing on this plateau phase, we performed powder XRD under pulsed fields up to 55 T. We observed that XRD peaks split at zero field coalesce into single, sharp peaks at high fields [D]. This behavior indicates that the lattice symmetry in the plateau phase is cubic, consistent with expectations for a 3-up-1-down magnetic structure.

References

[A] A. Ikeda, M. Gen et al., Phys. Rev. Lett. in press. [arXiv:2504.10085]
[B] M. Gen et al., J. Phys. Soc. Jpn. 93, 104602 (2024). (Original paper [29])
[C] M. Gen et al., Phys. Rev. Mater. 7, 104404 (2023). (Original paper [24])
[D] M. Gen et al., Phys. Rev. B 111, 214441 (2025). (Original paper [36])