Tunable Magnetic and Magnetocaloric Properties by Thermal Annealing in Erco2 Atomized Particles
Tunable Magnetic and Magnetocaloric Properties by Thermal Annealing in Erco2 Atomized Particles
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DOI：
10.1016/j.jallcom.2022.168040
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发表时间：
2022-11
期刊：
影响因子：
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通讯作者：
Takafumi D. Yamamoto;A. Saito;H. Takeya;K. Terashima;T. Numazawa;Y. Takano
中科院分区：
文献类型：
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作者：
Takafumi D. Yamamoto;A. Saito;H. Takeya;K. Terashima;T. Numazawa;Y. Takano
将磁热材料加工成具有合适形状的磁制冷剂对于磁制冷系统的发展至关重要。在这种情况下，加工对材料物理性能的影响是重要问题之一。在这里，我们调查的晶体学，磁性和磁热性能的气体雾化颗粒的金属间化合物ErCo 2，一个巨大的磁热材料的低温应用。结果表明，原子化和随后的热退火显著改变了ErCo2的物理性质。在雾化态粒子中，磁转变温度从34 K升高到56 K，相变从一级转变到二级。热退火使相变温度回到原来的温度，并恢复一级相变特性。磁性的变化与晶体学性质的变化密切相关，表明了磁结构耦合的重要性。粒子的磁熵变-Δ SM可以根据退火条件在大小、形状和峰值温度上进行调整。对于0 - 5 T的磁场变化，− Δ SM的峰值在9 - 33 J kg − 1K − 1的范围内变化。所有的ErCo 2雾化颗粒具有磁热性能相媲美或上级的其他有前途的候选人的低温磁制冷剂。
Processing magnetocaloric materials into magnetic refrigerants with appropriate shapes is essential for the development of magnetic refrigeration systems. In this context, the impact of processing on the physical properties of the materials is one of the important issues. Here, we investigate the crystallographic, magnetic, and magnetocaloric properties of gas-atomized particles of the intermetallic compound ErCo2, a giant magnetocaloric material for low-temperature applications. The results demonstrate that the physical properties of ErCo2are significantly changed by atomization and subsequent thermal annealing. In the as-atomized particles, the magnetic transition temperature increases from 34 to 56 K, and the phase transition changes from first order to second order. The thermal annealing shifts the transition temperature back to the original one and restores the first-order phase transition characteristic. The changes in magnetic properties are closely related to those in crystallographic properties, suggesting the importance of the magneto-structural coupling. The magnetic entropy change −ΔSMof the particles can be tuned in size, shape, and peak temperature depending on the annealing conditions. The peak value of −ΔSMvaries in the range of 9–33 J kg−1K−1for a field change of 0–5 T. All the ErCo2atomized particles have magnetocaloric properties comparable or superior to other promising candidates for low-temperature magnetic refrigerants.