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arXiv · 2605.00540

Incommensurate Magnetic Ordered Phase with Enhanced Low-Temperature Magnetic Specific Heat in SmAu$_3$Al$_7$

Ryuji Higashinaka·Takuma Iwami·Kohsuke Saitou·Takashi U. Ito·Chihiro Tabata·Koji Kaneko·Takashi Ohhara·Ryoji Kiyanagi·Akiko Nakao·Jumpei G. Nakamura·Wataru Higemoto·Akihiro Koda·Shinsaku Kambe·Yuji Aoki·Tatsuma D. Matsuda
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Abstract

Neutron scattering and muon spin rotation ($\mu$SR) measurements on single-crystal SmAu$_3$Al$_7$ reveal magnetically ordered states associated with successive transitions at $T_{\rm N}$ = 2.8 K and $T^*$ = 0.9 K. Magnetic Bragg peaks appear below $T_{\rm N}$ with an incommensurate (IC) propagation vector ${\bf q}$ = (0.30, 0, 1.33). $\mu$SR detects spontaneous internal fields below $T_{\rm N}$, and the spectral shape is consistent with the IC magnetic ordering. No anomalies are observed at $T^*$, indicating that the magnetic structure remains essentially unchanged below and above $T^*$. The magnetic order is revealed to be a spatially homogeneous long-range ordered state, rather than a partially disordered state proposed in earlier studies. The possible connection between the IC magnetic order and the enhanced low-temperature magnetic specific heat is discussed.

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Ryuji Higashinaka, Takuma Iwami, Kohsuke Saitou, Takashi U. Ito, Chihiro Tabata, Koji Kaneko, Takashi Ohhara, Ryoji Kiyanagi, Akiko Nakao, Jumpei G. Nakamura, Wataru Higemoto, Akihiro Koda, Shinsaku Kambe, Yuji Aoki, Tatsuma D. Matsuda. 2026-05-01. Incommensurate Magnetic Ordered Phase with Enhanced Low-Temperature Magnetic Specific Heat in SmAu$_3$Al$_7$. https://doi.org/10.7566/jpsj.95.063702

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