Emergent quasi-one-dimensional antiferromagnetism in the distorted kagome magnet CePtPb

Journal Article · Fri Feb 20 00:00:00 EST 2026 · Physical Review. B

DOI:https://doi.org/10.1103/hjkq-j6zb· OSTI ID:3020881

Li, Fangli ^[1]; Liu, Pengfei ^[1]; Fu, Ying ^[2]; Xu, Lei ^[3]; Ge, Han ^[1]; Yang, Jiong ^[2]; Bu, Huanpeng ^[1]; Hu, Biaoyan ^[2]; Zhao, Nan ^[4]; Li, Tiantian ^[5]; Yuan, Jiayue ^[1]; Zhang, Chen ^[1]; Liu, Junzhe ^[1]; Ouyang, Zhongwen ^[6]; Miao, Ping ^[7]; Sheng, Jieming ^[8]; Podlesnyak, Andrey A. ^[9]; Wu, Liusuo ^[2]

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1. Southern University of Science and Technology (SUSTech), Shenzhen (China)
2. Southern University of Science and Technology (SUSTech), Shenzhen (China); Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen (China)
3. Zhejiang University, Hangzhou (China)
4. Southern University of Science and Technology (SUSTech), Shenzhen (China); Spallation Neutron Source Science Center, Dongguan (China); Chinese Academy of Sciences (CAS), Beijing (China). Institute of High Energy Physics (IHEP)
5. City University of Hong Kong, Kowloon (Hong Kong)
6. Huazhong University of Science & Technology, Wuhan (China)
7. Spallation Neutron Source Science Center, Dongguan (China); Chinese Academy of Sciences (CAS), Beijing (China). Institute of High Energy Physics (IHEP)
8. Great Bay University (GBU), Dongguan (China). Great Bay Institute for Advanced Study
9. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

CePtPb hosts a distorted kagome lattice of Ce³⁺ ions, providing a clean platform to investigate how reduced local symmetry and strong spin-orbit coupling reshape frustrated magnetism. Magnetization, specific heat, and magnetocaloric effect measurements, combined with a symmetry analysis of the single-ion anisotropy, demonstrate that the local 𝑚⁢2⁢𝑚 site symmetry selects a nearly Ising-like Kramers doublet with easy axes lying within the 𝑎⁢𝑏 plane. This results in three distinct in-plane Ising directions and an overall easy-plane anisotropy. The low-energy magnetic response is well captured by a three-sublattice Ising model, which quantitatively reproduces the saturation magnetization for arbitrary in-plane field orientations, including $[110]$ and $$[1\bar{⁢1}⁢0]$$, as well as the ratio of the field-induced critical fields. For 𝐵∥$[110]$, the phase diagram exhibits two quantum critical points at 𝐵_c⁢1 = 0.25T and 𝐵_c⁢2 = 0.55T, arising from the sequential polarization of the three Ising sublattices. In conclusion, these results reveal that the system develops quasi-one-dimensional spin chains along the 𝑐 axis, emerging from the nominally three-dimensional crystal structure composed of stacked kagome layers, and illustrate how reduced local symmetry can drive effective dimensional reduction in rare-earth Ising magnets.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 3020881
• Journal Information: Physical Review. B, Journal Name: Physical Review. B Journal Issue: 6 Vol. 113; ISSN 2469-9969; ISSN 2469-9950
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English