Symmetry-Breaking Induced Exchange Bias in Ferromagnetic Ni-Cu-Co and Ni-Fe-Co Sandwiches Grown on a Vicinal Cu(001) Surface

Abstract

Ferromagnetic Ni-Cu-Co and Ni-Fe-Co sandwiches were grown epitaxially onto a vicinal Cu(001) substrate and investigated using magneto-optical Kerr effect and x-ray magnetic circular dichroism techniques. We find that the atomic steps of the vicinal surface break the magnetic reversal symmetry to induce an exchange bias in the Ni perpendicular magnetic hysteresis loop. The Ni exchange bias direction can be switched by changing the direction of the in-plane Co magnetization. In addition, the exchange bias can be tailored by changing the Cu or Fe spacer layer thickness.

Exchange bias of a ferromagnetic semiconductor by a ferromagnetic metal

“…Here, we demonstrate an antiferromagnetic coupling and exchange bias in Fe/(Ga,Mn)As bilayer films, by combining element-specific XMCD measurements and bulk-sensitive superconducting quantum interference device (SQUID) magnetometry. As with previous studies of FM metal/FM semiconductor bilayers 4,5 (and in contrast to AFM coupled FM metal/FM metal exchange bias structures 10,11 ) the layers are in direct contact without a non-magnetic spacer in between. We distinguish interface and bulk (Ga,Mn)As layers that are respectively strongly and weakly antiferromagnetically coupled to the Fe overlayer.…”

Symmetry-breaking interlayer Dzyaloshinskii–Moriya interactions in synthetic antiferromagnets

“…Other perpendicular indirect exchange interactions such as the biquadratic interlayer coupling (29) cannot account for the chiral nature of the observed effect. A crystalline texture substantially tilted with respect to the substrate plane, a possible source of perpendicular bias (30), is not a relevant factor in our samples (Supplementary 9). Furthermore, intra-layer DMI effects leading to asymmetric magnetic hysteresis processes have been only observed in laterally-patterned nanomagnets, and require the simultaneous application of orthogonal magnetic fields (31,32), in contast to our experiments.…”

Temperature and Magnetic Field-Assisted Switching of Magnetization and Observation of Exchange Bias in YbCrO3 Nanocrystals

“…However, the origin of NM and EB in orthochromites can be correlated, as the sign of H EB can be related to the magnetization reversal. The EB has been observed in various interfacial systems including ferromagnetic (FM)/anti-ferromagnetic (AFM), FM/ferrimagnet, FM/spin glass, core–shell structures, heterostructures, superlattices, etc. − The conventional EB is usually observed after field-cooling (FC) the material; however, in few systems, the ZFC EB is also observed . The presence of multiple phases resulted in the observed ZFC EB, which was later associated with an artifact, until a model to explain the positive ZFC EB was proposed .…”