Effect of dislocation pattern on the magnetic domain structure of pure polycrystalline Ni

We investigated the influence of discrete dislocation, dislocation cell, and cell block on the magnetic domain structure in deformed polycrystalline Ni. Discrete dislocation and dislocation cell structure manifested a short-range effect on the local domain structure. By contrast, dislocation cell block structure significantly changed the magnetic domain by generating 180° domain walls. Our observations indicated that the change of magnetic property as a function of plastic deformation should be discontinuous. However, in macroscale, the coercivity and hysteresis loss monotonically increased as increasing flow stress increases. The discrepancy between the phenomena at different scales is attributed to the crystallographic orientation change in plastic deformation.