Abstract
The magnetic domain structure and magnetization process in Sm2(Fe0.95,Mn0.05)17N5.0 powders are investigated by Lorentz microscopy and electron holography. The magnetic domain walls are aligned along the magnetization easy axis (c axis) and are connected with one another along amorphous layers that are distributed along the direction parallel to the c axis. On the other hand, it is found that the domain walls are always located in the amorphous layer after domain wall motion. These results reveal that the amorphous layers are the pinning centers of the domain walls. Thus, it is reasonable to consider that the coercivity of a Sm2(Fe0.95,Mn0.05)17N5.0 powder is strongly affected by the distribution of the amorphous layers in the powder.