晶粒易轴取向度对纳米晶永磁Pr_2Fe_(14)B磁性的影响

Influence of grain alignment degree on the magnetic properties for single-phase nanocrystalline Pr_2Fe_14)B magnets

构造了立方和不规则形状晶粒的各向异性纳米晶单相Pr2Fe14B磁体.利用微磁学的有限元法,模拟计算了样品的磁滞回线.计算结果表明,随着磁体晶粒易轴取向度的变差,磁体的剩磁、矫顽力均随之下降.不同晶粒尺寸的纳米晶单相Pr2Fe14B磁体,其磁性能随取向度的变化快慢不同,原因在于磁体中的晶间交换作用(IGEC)的强弱不同.随着晶粒取向度的提高,纳米晶单相磁体的矫顽力逐渐增加,这完全不同于烧结磁体.

The single-phase nanocrystalline Pr2Fe14B magnets composed of cubic-shaped and irregular-shaped grains is built. The magnetic hysteresis loops are simulated by micromagnetism finite element method. The remanence, coercivity and maximum energy product decrease with deteriorated grain alignment. Attributed to strong intergrain exchange coupling (IGEC), the variation of magnetic properties with alignment degree is significantly affected by the average grain size in nanocrystalline magnets. The investigation shows the increase of coercivity with improved grain alignment in nanocrystalline magnets, which is completely different from the phenomena in sintered magnets.