首页|Gd-La-Al合金的微观结构与磁热效应

Gd-La-Al合金的微观结构与磁热效应

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以Gd3-xLaxAl2(x=0,0.1,0.2,0.3)磁制冷材料为研究对象,系统分析了合金的相组成、微观组织及磁热性能.结果表明,Gd3-xLaxAl2(x=0,0.1,0.2,0.3)合金均由Gd3Al2相、GdAl相、Gd2Al相组成.La原子主要分布于Gd2Al相,且La元素的添加具有调控GdAI相形貌的作用.对M-T曲线求一阶导数可得,Gd3-xLaxAl2(x=0,0.1,0.2,0.3)合金的居里温度TC随La含量的增加呈逐渐降低的趋势,分别为275,267,261,252 K,适用于近室温领域的制冷.利用Landau理论,分析了 Gd3-xLaxAl2(x=0,0.1,0.2,0.3)合金的磁相变特征.分析拟合结果可知,Gd3-xLaxAl2(x=0,0.1,0.2,0.3)合金在居里温度TC附近发生二级磁相变.0~2 T磁场下Gd3Al2合金的最大等温磁熵变(△SM)max为3.05 J·kg-1·K-1,最大绝热温变(△Tad)max为2.12 K,表现出良好的磁热性能.
Microstructure and Magnetocaloric Effect of Gd-La-AI Alloy
Taking Gd3-xLaxAl2(x=0,0.1,0.2,0.3)magnetic refrigeration materials as the research object,the phase composition,microstructure and magnetocaloric properties were systematically analyzed.The results show that all Gd3-xLa-xAl2(x=0,0.1,0.2,0.3)alloys are composed of Gd3Al2 phase,GdAl phase and Gd2Al phase.La atoms are mainly distributed in Gd2Al phase and the addition of La can regulate the morphology of GdAl phase.The Curie temperature TC of Gd3-xLaxAl2(x=0,0.1,0.2,0.3)alloys decreases gradually with the in-crease of La content,which is 275,267,261 and 252 K,respectively.The magnetic transition characteristics of Gd3-xLaxAl2(x=0,0.1,0.2,0.3)alloys were analyzed by Landau theory.The fitting results show that Gd3-xLaxAl2(x=0,0.1,0.2,0.3)alloys have the advantage of low hysteresis due to second-order magnetic phase transition near Curie temperature TC.The maximum isothermal magnetic entropy change(△SM)max of Gd3Al2 alloy is 3.05 J·kg-1·K-1,and the maximum adiabatic temperature change(△Tad)max is 2.12 K,showing excellent magnetocalo-ric properties.

magnetic refrigeration materialmicrostructuremagnetic phase transitionmagnetocaloric propertiesrare earths

高磊、戴默涵、程娟、刘翠兰、王鹏宇、李兆杰

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包头稀土研究院 白云鄂博稀土资源研究与综合利用国家重点实验室,内蒙古包头 014030

磁制冷材料 微观组织 磁相变 磁热性能 稀土

"十四五"国家重点研发计划重点专项(2021)内蒙古自然科学基金

2021YFB35012002021MS05016

2024

中国稀土学报
中国稀土学会 北京有色金属研究总院

中国稀土学报

CSTPCD北大核心
影响因子:1.175
ISSN:1000-4343
年,卷(期):2024.42(1)
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