Coercivity enhancement of Dy-coated Nd-Fe-B flakes by crystallization
Coercivity enhancement of Dy-coated Nd-Fe-B flakes by crystallization
复制标题
DOI：
10.1063/1.3549604
复制
发表时间：
2011-04
影响因子：
3.2
通讯作者：
H. Fukunaga;Y. Sugimoto;M. Nakano;T. Yanai;S. Ohta;M. Itakura;M. Nishida
中科院分区：
文献类型：
--
作者：
H. Fukunaga;Y. Sugimoto;M. Nakano;T. Yanai;S. Ohta;M. Itakura;M. Nishida
各向同性Dy包覆Nd-Fe-B薄片的结晶和Dy从其表面的同时扩散增强了其磁性。非晶Dy包覆Nd-Fe-B薄片通过加热至923 K2 2 min后快速冷却而晶化。在结晶过程中，表面的Dy扩散到薄片中。这种低温快速退火产生具有细晶粒的薄片，并且Dy扩散增强了它们的结晶性。晶化后的矫顽力随Dy层厚度的增加而增加，但当Dy层厚度超过3 μm时，剩磁下降。超过6 μm的厚涂层导致DyFe 2的形成，这降低了结晶薄片的磁性能。3 μ m厚的涂层片经退火处理后具有优异的磁性能：矫顽力为1880 kA/m，剩磁为78 emu/g。这种磁化率比未涂覆的薄片高约500 kA/m，而剩磁与未涂覆的薄片相当。
The coercivity of isotropic Dy-coated Nd-Fe-B flakes was enhanced by crystallization and simultaneous diffusion of Dy from their surfaces. Amorphous Dy-coated Nd-Fe-B flakes were crystallized by heating them to 923 K 2over a 2 min period followed by rapid cooling. During crystallization, the Dy on the surface diffused into the flakes. This low-temperature rapid annealing produced flakes with fine grains and the Dy diffusion enhanced their coercivity. The coercivity after crystallization increased with increasing Dy layer thickness, although the remanence decreased when the layer thickness exceeded 3 μm. Thick coatings of over 6 μm resulted in the formation of DyFe2, which degraded the magnetic properties of the crystallized flakes. Flakes with a 3-μm-thick coating exhibited excellent magnetic properties after annealing: They had a coercivity of 1880 kA/m and a remanence of 78 emu/g. This coercivity is approximately 500 kA/m higher than that of uncoated flakes, whereas the remanence is comparable to that o...