Controlling the switching field in nanomagnets by means of domain-engineered antiferromagnets

Abstract

Using soft x-ray spectromicroscopy, we investigate the magnetic domain structure in embedded nanomagnets defined in La${}_{0.7}$Sr${}_{0.3}$MnO${}_3$ thin films and LaFeO${}_3$/La${}_{0.7}$Sr${}_{0.3}$MnO${}_3$ bilayers. We find that shape-controlled antiferromagnetic domain states give rise to a significant reduction of the switching field of the rectangular nanomagnets. This is discussed in the framework of competition between an intrinsic spin-flop coupling and shape anisotropy. The data demonstrates that shape effects in antiferromagnets may be used to control the magnetic properties in nanomagnets.