Controlling the angle between magnetic moments of Co layers in Co|RuCo|Co

Abstract

Spintronic devices would greatly benefit from a noncollinear alignment between magnetizations of adjacent ferromagnetic layers for maximum performance and reliability. We demonstrate that such an alignment can be created and controlled by coupling two ferromagnetic layers across a magnetic spacer layer consisting of a nonmagnetic material, Ru, alloyed with a ferromagnetic element, Co. Changing the composition and thickness of the spacer layer enables the control of the relative angle between the magnetizations of the ferromagnetic layers between [Formula: see text] and [Formula: see text]. The onset of noncollinear alignment between the ferromagnetic layers coincides with the advent of magnetic order in the spacer layer. This study maps the concentration and thickness ranges of RuCo spacer layers that give rise to noncollinearity between ferromagnetic Co layers. The experimental results are successfully reproduced by simulating our structures with an atomistic model. This model assumes that Co atoms in the RuCo spacer layer have magnetic moments and that neighboring Co atoms are ferromagnetically coupled, while Co atoms separated by one or more Ru atoms are antiferromagnetically coupled.

Magneto-optical detection of non-collinear magnetization states in ferromagnetic multilayers

“…The FM interlayer exchange coupling phenomenon describes the effect of magnetic interactions in between FM layers that are physically separated by a NM material [8,33], as it is represented in figure 1. It has been previously studied with two FM thin layers separated by a coupling layer, which should be either NM or weakly FM in order to mediate a weak FM coupling and it should also provide a good template for the growth of the second FM layer [34].…”