Magnetic domain walls at the edge of patterned NiO/NiFe bilayers

Abstract

AbstractThe magnetic domain walls at the edges of a large patterned and exchange‐biased NiO (10–60 nm)/NiFe (10 nm) bilayers and their motions with applied field were investigated by MFM. Three kinds of domain walls were found at the edges of the NiO (30 nm)/NiFe (10 nm) bilayer having the exchange biasing field (Hex) of 21 Oe. Two zigzag charged walls and Néel wall appeared at the edges perpendicular and parallel to Hex, respectively. The zigzag charged walls are nearly a factor of three wider than the Néel wall, and were not observed for the strong exchange‐biased bilayer (60 nm NiO, H ex = 75 Oe). We investigated the subsequent motion of the walls, and identified the pinning and nucleation sites during magnetization reversal. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)