环氧树脂粘结Sm_2Fe_(17)N_x磁体的矫顽力机理

Coercivity Mechanism of Epoxy Resin Bonded Sm_2Fe_(17)N_x Magnets

研究了环氧树脂粘结Sm2Fe17Nx磁体的矫顽力防外磁场和温度的变化规律。结果表明，随着磁场的增加，矫顽力及剩余磁感应强度开始时快速增大，高场后增加缓慢并趋于饱和。低场时非取向样品比取向样品的矫顽力大，外场反平行于取向方向比平行于取向方向的矫顽力大，而在足够大的外场下二者趋于相等。随着温度的升高，矫顽力逐渐降低．由矫顽力与温度的关系，推导出显微结构参数α＝0．31。这都说明环氧树脂粘结SmFeN磁体的矫顽力机理主要是形核机制。另一方面，随着SmFeN粉末粒度的减小，矫顽力逐渐上升，以及矫顽力随各向异性场的增加而增大，也显示了矫顽力机理兼有单畴颗粒孩矩转动机制。

In the present work,the field and temperature dependence of the coercive field for Sm2Fe17Nx epoxy resin bonded magnets is investigated. The results indicate that as the magnetizing field increases, both the coercivity and remanence increase sharply up to a certain high field and then slowly increase to a saturated value. In a low magnetizing field the coercivity of the non-aligned magnet is higher than that of the aligned magnet; the coercivity of the sample magnetized antiparallel to the aligned direction is higher than that of the sample magnetized parallel to the aligned direction. If the magnetizing field is high enough,both of these coercivities become nearly the same. As the temperature increases, the coercivity decreases gradually. The microstructural factor derived from the temperature dependence of the coercivity is 0. 31. All these results imply that nucleation mechanism could be responsible for the magnetic hardening of the SmFeN epoxy resin bonded magnets. On the other hand, the coercivity increase with the anisotropy field increasing and partial size decreasing indicates that the magnetic hardening may be attributed partly to the sing1e domain particle mechanisn.