Exchange shift of stripe domains in antiferromagnetically coupled multilayers

TL;DR

This paper demonstrates that antiferromagnetic interlayer exchange in multilayers causes a relative shift of stripe domains, explaining observed phenomena and enabling quantitative analysis of exchange interactions.

Contribution

It introduces the concept of exchange shift caused by interlayer exchange and derives analytical relations to quantify this effect in multilayers.

Findings

Exchange shift causes domain wall broadening.

Formation of tiger-tail patterns explained.

Analytical relations enable measurement of exchange strength.

Abstract

Antiferromagnetically coupled multilayers with perpendicular anisotropy, as [CoPt]/Ru, Co/Ir, Fe/Au, display ferromagnetic stripe phases as the ground states. It is theoretically shown that the antiferromagnetic interlayer exchange causes a relative shift of domains in adjacent layers. This ``exchange shift'' is responsible for several recently observed effects: an anomalous broadening of domain walls, the formation of so-called ``tiger-tail'' patterns, and a ``mixed state'' of antiferromagnetic and ferromagnetic domains in [CoPt]/Ru multilayers. The derived analitical relations between the values of the shift and the strength of antiferromagnetic coupling provide an effective method for a quantitative determination of the interlayer exchange interactions.