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arXiv · 2506.15394

Successive Phase Transitions in the Quasi-Kagome Lattice System URhSn Studied by Resonant X-ray Scattering

Chihiro Tabata·Fusako Kon·Ruo Hibino·Yusei Shimizu·Hiroshi Amitsuka·Koji Kaneko·Yoshiya Homma·Dai Aoki·Hironori Nakao
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Abstract

Successive phase transitions in the quasi-kagome compound URhSn were investigated by resonant X-ray scattering (RXS) at the uranium $M_4$ edge. In the high-temperature phase between 16 K and 54 K, an additional RXS signal was detected superposed onto fundamental reflections in both $\pi$-$\sigma'$ and $\pi$-$\pi'$ polarization channels. Upon cooling below 16 K, reported as a ferromagnetic phase along $c$, substantial enhancements were observed again in the both polarization channels at the 300 reflection, demonstrating a simultaneous emergence of in-plane spin alongside the $c$-axis ferromagnetic components. The observed behavior can be interpreted by an antiferro-quadrupole (AFQ) order of $O_{yz}$ or $O_{zx}$ characterized by a propagation vector $q = 0$ in the intermediate phase, which then coexists with a ferromagnetic component below 16 K. The resulting ground state structure breaks the mirror symmetry perpendicular to the kagome plane, identifying the formation of a unique AFQ order with either chirality or polarity in URhSn.

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Chihiro Tabata, Fusako Kon, Ruo Hibino, Yusei Shimizu, Hiroshi Amitsuka, Koji Kaneko, Yoshiya Homma, Dai Aoki, Hironori Nakao. 2025-06-18. Successive Phase Transitions in the Quasi-Kagome Lattice System URhSn Studied by Resonant X-ray Scattering. https://doi.org/10.7566/jpsj.94.083701

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