Transition micromagnetic structures in asymmetric vortexlike domain walls (Static solutions and dynamic reconstructions)

Abstract

Abstract-The possible types of transition structures with a three dimensional magnetization distribution over regions in the vortex asymmetric domain walls that exist in magnetically uniaxial soft magnetic films with in plane anisotropy are studied by computer simulation in terms of a micromagnetic approach. It is shown that the possible structure types include both the type of vertical Bloch lines that was discussed earlier in other works and new types, namely, singular (Bloch) points and clusters consisting of vertical Bloch lines and Bloch points. The spatial configurations of the transition structures are calculated and their topological properties are found. The numerical simulation of the dynamics of closely spaced substructure regions reveals various scenarios of their interaction, including annihilation accompanied by energy release and the excitation of nonlinear waves.

Numerical studies of micromagnetic configurations in stripes with in-plane anisotropy and low quality factor

“…Performing the simulations to compare those walls energy with the cross-tie wall one, we assumed the asymmetric Bloch and Néel walls structure to be homogeneous along z. It was found (see for example [30]) that inhomogeneities in asymmetric Bloch wall structure along the easy axis (Bloch lines or singular points) increase the wall energy.…”

3-D Simulations of Micromagnetic Transition Structures in Vortex Asymmetric Domain Walls

“…Since all these orientations are energetically equivalent, they have equal likelihood to be observed in real films, possibly in the same wall. The static structures of possible transitions from one wall segment to another (transition micromagnetic structures -TMSs, including special cases of vertical Bloch lines -VBLs) were studied numerically in [3,4]. Kerr magnetooptical domain, domain walls and TMSs observations were reported in [2].…”

“…Symbols X and Y denote various types of the VBL and the asterisk denotes the Bloch point (SP). Configurations of the magnetization in the VBLs have been described in details in [4]. The sequence of the pictograms read from left to right reflects the order in which TMSs, SPs and domain wall regions are met along the z axis in the positive direction (see Fig.…”