富稀土相对晶界扩散Nd_(2)Fe_(14)B磁体微结构与磁性能的影响  

Influence of rare earth-rich phase on the microstructure and magnetic properties of grain boundary diffused Nd_(2)Fe_(14)B magnet

作　　者：王世平 马强 苏满有[2] WANG Shi-ping;MAQiang;SU Man-you(Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources,Inner Mongolia University of Science and Technology,Baotou 014000,China;College of Science,Inner Mongolia University of Science and Technology,Baotou 014000,China)

机构地区：[1]内蒙古科技大学内蒙古自治区白云鄂博矿多金属资源综合利用重点实验室,内蒙古包头014000 [2]内蒙古科技大学理学院,内蒙古包头014000

出　　处：《磁性材料及器件》2022年第3期9-15,共7页Journal of Magnetic Materials and Devices

摘　　要：利用磁控溅射技术制备了重稀土元素Tb晶界扩散的Nd_(2)Fe_(14)B磁体,研究了不同富稀土相磁体晶界扩散后的微观结构和磁性能。在最佳热处理温度950℃扩散和520℃退火的基础上,两种不同富稀土相磁体的矫顽力从11.96 kOe和13.37 kOe分别增加至18.97 kOe和22.85 kOe,但剩磁变化不明显;富稀土相较多的磁体相对于较少的磁体矫顽力增幅提高了35.2%。研究发现,重稀土元素Tb在晶界扩散中替代了磁体晶粒外延层的Nd,形成了(Nd,Tb)_(2)Fe_(14)B核-壳结构;而凭借较多的富稀土相形成的扩散通道,使Tb更为顺畅地扩散到磁体内部,有效隔离晶粒,起到良好的交换去耦合作用。磁畴观察发现,随扩散的深入,富稀土相较多的磁体能形成更多的核-壳结构,晶粒表面磁畴反转域较少,利于矫顽力提高。微成分分析研究表明,有效地控制富稀土相的含量和分布可进一步提高晶界扩散磁体的磁性能。Nd_(2)Fe_(14)B magnets with heavy rare earth element Tb grain boundary diffusion were prepared by magnetron sputtering technology,and the different rare-earth-rich phase grain boundary diffusion microstructure and magnetic properties were researched.Based on the optimal heat treatment temperature of 950℃for diffusion and 520℃for annealing,the coercivity of the two different rare-earth-rich phase magnets increased from 11.96 kOe and 13.37 kOe to 18.97 kOe and 22.85 kOe,respectively,but the remanence did not change significantly.Magnets with more rare earth phases have a 35.2%increase in coercivity compared with less magnets.The study found that the heavy rare earth element Tb replaced the Nd of the magnet grain epitaxial layer in the grain boundary diffusion,forming a(Nd,Tb)_(2)Fe_(14)B core-shell structure,and the diffusion channels formed by more rare earth-rich phases make Tb diffuses more smoothly into the inside of the magnet,effectively isolates the crystal grains,and plays a good role of exchange decoupling.Observation of magnetic domains shows that with the deepening of diffusion,magnets with more rare earth-rich phases can form more core-shell structures,and there are fewer magnetic domain reversal domains on the crystal grain surface,which is beneficial to increase the coercivity.Micro-composition analysis studies have shown that effectively controlling the content and distribution of the rare earth-rich phase can further improve the magnetic properties of grain boundary diffusion magnets.

关 键 词：Nd-Fe-B烧结磁体 磁控溅射 Tb晶界扩散 矫顽力 磁畴 

分 类 号：TM273[一般工业技术—材料科学与工程]