垂直取向Nd2Fe14B/α-Fe磁性三层膜的磁化反转

Magnetization reversal of perpendicularly orientated Nd_2Fe_(14)B/α-Fe trilayer

运用微磁学方法结合物质参数探究了垂直取向Nd2Fe14B/α-Fe磁性三层膜的磁化反转过程,计算出成核场、钉扎场以及磁滞回线随Ls(软磁相厚度)的变化,并与相关的实验和理论数据进行比较.由于考虑了退磁能量项,垂直取向的成核场比平行取向时低,在外磁场还没有反向时就发生了成核.随着软磁相厚度的增加,理论矫顽力从等于成核场(同时也等于钉扎场),到等于钉扎场,再到小于钉扎场,矫顽力机理由成核变为钉扎.

The full magnetization reversal process of perpendicular orientated Nd2 Fe14 B/α-Fe trilayer has been investigated by using a mieromagnetic method. Both nucleation and pinning fields as well as hysteresis loops have been calculated reliably as functions of Ls （soft layer thickness）. In addition, detailed comparison between our results and experimental data has been done. With the demagnetization energy considered, the nucleation field of perpendicular by orientated case is lower than the parallel one and the nucleation oeeus before the reversal of the applied field. For small Ls, the theoretical coereivity equals to the nucleation field （it equals to pinning filed also）. As the thickness of the soft phase increases, the coercivity mechanism changes from nucleation to pinning. For large L^s, however, the coercivity is slightly smaller than the pinning field.