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arXiv · 2407.17830

Magnetic properties of AlB$_2$-type holmium silicides and germanides

G. Eguchi·R. Matsumoto·K. Terashima·Y. Takano
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Abstract

Discovery of the large magnetocaloric effect in HoB$_2$ has highlighted the practical advantage of heavy rare-earth ions. Other holmium compounds are of interest, and we here report the synthesis and the magnetic properties of HoSi$_{1.67}$ and HoGe$_{1.67}$ which form the same AlB$_2$-type structure but with vacancies. They are found to show the antiferromagnetic order with the Neel temperature 17.6(2)K for HoSi$_{1.67}$ and 9.9(2)K for HoGe$_{1.67}$, and the magnetic entropy changes at the temperature are 0.05(1)J/cm$^3$K for HoSi$_{1.67}$ and 0.08(1)J/cm$^3$K for HoGe$_{1.67}$. Magnetic orders were suppressed by replacing vacancies with nickel, resulting in an increase of magnetic entropy changes. Distance between the in-plane Ho$^{3+}$ ions appears to be an important parameter leading to the transition between the antiferromagnetic (HoSi$_{1.67}$) and the ferromagnetic (HoB$_2$) order. The finding may aid the exploration of other heavy rare-earth compounds for similar applications.

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G. Eguchi, R. Matsumoto, K. Terashima, Y. Takano. 2024-07-25. Magnetic properties of AlB$_2$-type holmium silicides and germanides. https://arxiv.org/abs/2407.17830

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