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arXiv · 2005.12000

Effect of Dy substitution in the giant magnetocaloric properties of HoB$_{2}$

Pedro Baptista de Castro·Kensei Terashima·Takafumi D. Yamamoto·Suguru Iwasaki·Ryo Matsumoto·Shintaro Adachi·Yoshito Saito·Hiroyuki Takeya·Yoshihiko Takano
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Abstract

Recently, a massive magnetocaloric effect near the liquefaction temperature of hydrogen has been reported in the ferromagnetic material HoB$_{2}$. Here we investigate the effects of Dy substitution in the magnetocaloric properties of Ho$_{1-x}$Dy$_{x}$B$_{2}$ alloys ($\textit{x}$ = 0, 0.3, 0.5, 0.7, 1.0). We find that the Curie temperature ($\textit{T}$$_{C}$) gradually increases upon Dy substitution, while the magnitude of the magnetic entropy change |$\Delta \textit{S}_{M}$| at $\textit{T}$ = $\textit{T}_{C}$ decreases from 0.35 to 0.15 J cm$^{-3}$ K$^{-1}$ for a field change of 5 T. Due to the presence of two magnetic transitions in these alloys, despite the change in the peak magnitude of |$\Delta \textit{S}_{M}$|, the refrigerant capacity ($\textit{RC}$) and refrigerant cooling power ($\textit{RCP}$) remains almost constant in all doping range, which as large as 5.5 J cm$^{-3}$ and 7.0 J cm$^{-3}$ for a field change of 5 T. These results imply that this series of alloys could be an exciting candidate for magnetic refrigeration in the temperature range between 10-50 K.

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Pedro Baptista de Castro, Kensei Terashima, Takafumi D. Yamamoto, Suguru Iwasaki, Ryo Matsumoto, Shintaro Adachi, Yoshito Saito, Hiroyuki Takeya, Yoshihiko Takano. 2020-05-25. Effect of Dy substitution in the giant magnetocaloric properties of HoB$_{2}$. https://doi.org/10.1080/14686996.2020.1856629

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