کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1621983 | 1516399 | 2009 | 5 صفحه PDF | دانلود رایگان |

The effect of microstructure on the anisotropy and the coercivity in HDDR Nd–Fe–B magnet has been investigated by putting forward a theoretical anisotropy model influenced simultaneously by both the structure defect and the exchange coupling interaction. The results showed that the coercivity is greatly influenced by both the defect thickness, r0, and the anisotropy constant, K1(0), at grain surface. Coercivity is determined by the pinning mechanism when K1(0) ≤ 0.4K1 and r0 < 4 nm or K1(0) > 0.4K1. However, it is controlled by the nucleation mechanism when K1(0) ≤ 0.4K1 and r0 > 8 nm. For all values of K1(0), the coercivity first increases, reaches the maximum and then decreases with increasing r0, and its maximum value decreases with increasing K1(0). The maximum coercivity is 1102 KA/m while K1(0) = 0 and r0 is close to the thickness of domain wall (∼4 nm), which is consistent with experimental results given by other authors.
Journal: Journal of Alloys and Compounds - Volume 478, Issues 1–2, 10 June 2009, Pages 303–307