纳米晶永磁Pr8Fe87B5反磁化机理研究

用熔体快淬法制备了Pr2Fe14B/α-Fe纳米复合永磁样品.测量了样品的起始磁化、反磁化过程、矫顽力和剩磁与外场的关系，以及样品的磁粘滞性.经分析认为材料的矫顽力主要由非均匀的钉扎机理决定，但由于交换硬化的软磁相的可逆转动使得这种反磁化机理不同于单相永磁材料的钉扎行为.磁粘滞性表明热激活主要源于硬磁相的不可逆磁化行为. 关键词： 纳米复合永磁 矫顽力 剩磁 磁粘滞

Mechanism of magnetization reversal in nanocrystalline Pr8Fe87B5

Nanocomposite Pr2Fe14B/α-Fe was prepared by melt spinning. The magnetization reversal has been examined by the initial magnetization curve, recoil curve, minor hysteresis loops, applied field dependence of coercivity and remanence, and thermal activation. Inhomogeneous pinning controls mainly the coercivity in the melt-spun ribbons. Due to the intergrain exchange coupling between soft and hard phases, the magnetization reversal is different from that in traditional permanent magnets. Thermal activation is determined by the irreversible magnetization of the hard phase.