Xu Qiao-Fei, Chen Man-Ting, Wu Ruo-Tong, Long La-Sheng, Zheng Lan-Sun
Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
J Am Chem Soc. 2024 Jul 24;146(29):20116-20121. doi: 10.1021/jacs.4c04258. Epub 2024 Jul 15.
Adiabatic demagnetization refrigeration (ADR) is a promising cooling technology with high efficiency and exceptional stability in achieving ultralow temperatures, playing an indispensable role at the forefront of fundamental and applied science. However, a significant challenge for ADR is that existing magnetic refrigerants struggle to concurrently achieve low magnetic ordering temperatures () and substantial magnetic entropy changes (-Δ) at ultralow temperatures. In this work, we propose the combination of Gd and Yb to effectively regulate both -Δ and in ultralow temperatures. Notably, the -Δ values for GdYbF () and GdYbF () in the 0.4-1.0 K range exceed those of all previously reported magnetic refrigerants within this temperature interval, positioning them as the most efficient magnetic refrigerants for the third stage to date. Although the -Δ values for GdYbF () in 1-4 K are less than those of the leading magnetic refrigerant Gd(OH)F, the -Δ values for GdYbF () in 1-4 K at 2 T surpass those of all magnetic refrigerants previously documented within the same temperature range, making it the superior magnetic refrigerant for the fourth stage identified thus far.
绝热去磁制冷（ADR）是一种很有前景的制冷技术，在实现超低温方面具有高效率和卓越的稳定性，在基础科学和应用科学前沿发挥着不可或缺的作用。然而，ADR面临的一个重大挑战是，现有的磁性制冷剂在超低温下难以同时实现低磁有序温度（）和显著的磁熵变（-Δ）。在这项工作中，我们提出将钆（Gd）和镱（Yb）结合起来，以有效地在超低温下调节-Δ和。值得注意的是，GdYbF（）和GdYbF（）在0.4 - 1.0 K范围内的-Δ值超过了该温度区间内此前报道的所有磁性制冷剂，使其成为迄今为止第三级最有效的磁性制冷剂。尽管GdYbF（）在1 - 4 K时的-Δ值小于领先的磁性制冷剂Gd(OH)F，但GdYbF（）在2 T时1 - 4 K的-Δ值超过了此前在相同温度范围内记录的所有磁性制冷剂，使其成为迄今为止确定的第四级最佳磁性制冷剂。
