2:14:1型高熵稀土永磁材料的反磁化机理  

Mechanism of magnetization reversal of 2∶14∶1 high-entropy rare-earth permanent magnets

作　　者：史镇华 胡新哲 周厚博 田正营 胡凤霞[2] 陈允忠[2] 孙志刚 沈保根[2,4,5] SHI Zhenhua;HU Xinzhe;ZHOU Houbo;TIAN Zhengying;HU Fengxia;CHEN Yunzhong;SUN Zhigang;SHEN Baogen(College of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China;State Key Laboratory of Magnetism,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;Shanxi Key Laboratory of Magnetoelectric Functional Materials and Application,Taiyuan University of Science and Technology,Taiyuan 030024,China;Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou 341000,China;Ningbo Institute of Materials Technology&Engineering,Chinese Academy of Sciences,Ningbo 315201,China)

机构地区：[1]太原科技大学材料科学与工程学院,太原030024 [2]中国科学院物理研究所,磁学国家重点实验室,北京100190 [3]太原科技大学,山西省磁电功能材料与应用重点实验室,太原030024 [4]中国科学院赣江创新研究院,赣州341000 [5]中国科学院宁波材料技术与工程研究所,宁波315201

出　　处：《物理学报》2025年第2期198-205,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12174297,12204342);基础科学中心项目(批准号:52088101);山西省基础研究计划(批准号:202103021224283,202203021212323);太原科技大学科研启动基金(批准号:20222015,20222002);来晋工作优秀博士奖励项目(批准号:20222039,20222040);山西省高等学校科技创新项目(批准号:2022L288)资助的课题.

摘　　要：稀土元素具有相似的基态电子性质,其独特的镧系收缩效应可以降低高熵材料中稀土元素的混合焓,这对于制备廉价且高性能的高熵稀土金属间化合物至关重要.本文在分析磁化和反磁化曲线的基础上,辅以Henkel曲线和磁黏滞系数S计算,研究了Nd_(11.76)Fe_(82.36)B_(5.88)(NdFeB),以及高熵稀土永磁合金化合物(La_(0.2)Pr_(0.2)Nd_(0.2)Gd_(0.2)Dy_(0.2))_(11.76)Fe_(82.36)B_(5.88)和(La_(0.2)Pr_(0.2)Nd_(0.2)Gd_(0.2)Tb_(0.2))_(11.76)Fe_(82.36)B_(5.88)等快淬条带的反磁化机理.研究结果发现,与纯NdFeB相比,高熵稀土永磁材料的晶间耦合作用显著增强,而磁偶极相互作用减弱.这表明,含重稀土的高熵材料中元素扩散机制在使样品均匀化的同时,其矫顽力有大幅度提高,矫顽力机制为硬磁相晶粒中的反磁化畴形核.(La_(0.2)Pr_(0.2)Nd_(0.2)Gd_(0.2)Dy_(0.2))_(11.76)Fe_(82.36)B_(5.88)的磁黏滞系数大于纯NdFeB,(La_(0.2)Pr_(0.2)Nd_(0.2)Gd_(0.2)Tb_(0.2))11.76 Fe_(82.36)B_(5.88)由于硬磁相反转与磁晶间耦合作用不同步,导致样品在具有较大各向异性场的同时,磁黏滞系数较小.这表明高熵稀土永磁材料的反磁化机理与传统稀土永磁材料显著不同,值得进一步深入研究.Rare-earth elements share similar ground-state electronic properties,and their unique lanthanide contraction effect can lower the mixing enthalpy of rare-earth elements in high-entropy materials,which is of great significance for fabricating low-cost and high-performance high-entropy rare-earth intermetallic compounds.In this work,the magnetization reversal mechanisms of rapidly quenched ribbons such as Nd_(11.76)Fe_(82.36)B_(5.88)(NdFeB)and the relevant high-entropy rare-earth permanent magnet alloy compounds(La_(0.2)Pr_(0.2)Nd_(0.2)Gd_(0.2)Dy_(0.2))_(11.76)Fe_(82.36)B_(5.88)and(La_(0.2)Pr_(0.2)Nd_(0.2)Gd_(0.2)Tb_(0.2))_(11.76)Fe_(82.36)B_(5.88)are studied by analyzing the magnetization and demagnetization curves,supplemented by Henkel curves and magnetic viscosity coefficient S.Compared with the pure NdFeB sample,the high-entropy rare-earth permanent magnet has the inter-grain exchange coupling significantly enhanced and the magnetic dipole interaction weakened,indicating that the element diffusion mechanism in heavy rare-earth containing high-entropy material homogenizes the sample,and significantly increases the coercivity.The mechanism of the coercivity is the nucleation of magnetization reversal domains in the grains of the hard magnetic phase.The magnetization mechanism is dominated by pinning at low magnetic fields and by nucleation at high magnetic fields,which is different from the magnetization mechanism of pure NdFeB and has some similarities with the self-pinning mechanism.The magnetic viscosity coefficient of(La_(0.2)Pr_(0.2)Nd_(0.2)Gd_(0.2)Dy_(0.2))_(11.76)Fe_(82.36)B_(5.88)is larger than that of pure NdFeB.Due to the asynchrony of hard magnetic phase reversal and intergranular magnetic coupling in(La_(0.2)Pr_(0.2)Nd_(0.2)Gd_(0.2)Tb_(0.2))_(11.76)Fe_(82.36)B_(5.88),the magnetic viscosity coefficient is small but the anisotropy field is large.This indicates that high-entropy sample reduces the magnetocrystalline anisotropy field barrier but increases the magnetocrystalline coupling length.This sugge

关 键 词：高熵永磁体 HENKEL 磁晶间耦合作用 磁黏滞系数 

分 类 号：TM273[一般工业技术—材料科学与工程]