Induced magnetic anisotropies dependent micromagnetic structure of epitaxial Co nanostrip arrays

Abstract

Dipole-dipole interaction in the arrays of closely packed magnetic nanostrips plays an important role in the magnetization reversal processes and significantly affects the critical fields, spin dynamics, and magnetotransport properties. Shape anisotropy in such arrays leads to the closure of the magnetic flux at the poles of adjacent nanostrips. If to induce the magnetic anisotropy oriented across the nanostrip long axis, this will change the micromagnetic configuration of each nanostrip in the array due to the appearance of the domain structure formed by domains with an antiparallel orientation of the magnetization. In this paper, we study the field-dependent behavior of vortex and Neel domain walls of the laminar domain structure of the dipolarly coupled epitaxial Co/Pd nanostrips with mutually perpendicular anisotropies induced by the atomic steps on the surface and by the long shape of nanostrips. We investigate the effect of dipole–dipole interaction between nanostrips on the magnetization reversal modes and switching fields depending on direction of the applied magnetic field. Our investigation reveals rather complex mechanisms of magnetization reversal of the nanostrip arrays, which can be described using a combination of processes including magnetization curling, transverse domain wall nucleation and motion as well as coherent rotation of spins within domains.