Magnetoelastic resonance as a probe for exchange springs at antiferromagnet-ferromagnet interfaces

Abstract

In prototype ferromagnet-antiferromagnet interfaces we demonstrate that surface acoustic waves can be used to identify complex magnetic phases arising upon evolution of exchange springs in an applied field. Applying sub-GHz surface acoustic waves to study the domain structure of the ferromagnetic layer in exchange-biased bilayers of ${\mathrm{Ir}}_{20}{\mathrm{Mn}}_{80}\ensuremath{-}{\mathrm{Co}}_{60}{\mathrm{Fe}}_{20}{\mathrm{B}}_{20}$, we are able to associate the magnetoelastic resonance with the presence of the exchange spin-spirals in both the ferromagnetic and antiferromagnetic layer. Our findings offer a complementary, integrative insight into emergent magnetic materials for applications of noncollinear spin textures in view of low-energy-consumption spintronic devices.