Domain wall creep in a 2D magnetic wire in the presence of antiferromagnetic coupling

Abstract

We have studied the dynamics of propagation in one dimension of a magnetic domain wall (DW) in the presence of an exchange bias field in nanowires patterned in two-dimensional ultra-thin perpendicularly magnetized ferromagnetic-antiferromagnetic (F-AF) films. The DW velocity v(H) is strongly reduced when the DW propagates against the exchange bias field, and its field dependence is consistent with a creep process with a critical exponent μ = 1/4. The increase in energy barrier responsible for the reduction of v(H) cannot be explained by the introduction of a macroscopic exchange bias field. Instead it arises from the AF-F interface that provides an extra-source of random pinning. © 2013 IOP Publishing Ltd.