Exchange coupling in metallic multilayers with a top FeRh layer

Abstract

We study magnetic properties of metallic multilayers with FeRh/ferromagnet interfaces grown by low-temperature molecular beam epitaxy. Room-temperature coercivity of the ferromagnetic layers is significantly enhanced after the growth of FeRh, proving the existence of the exchange coupling between the antiferromagnetic FeRh layer and the ferromagnetic layer. However, exchange bias is not clearly observed probably due to the presence of disordered structures, which result from the lattice strain at the FeRh/ferromagnet interfaces due to the lattice mismatch. We infer that the lattice matched interface between FeRh and ferromagnetic layers is a key parameter for controlling magnetic switching fields in such multilayer systems.

Graded magnetic materials

“…In most cases, the new physics and functionality arise from the discrete boundaries between disparate materials such as in the case of GMR or as in artificial FM/heavy-metal multilayers [29][30][31][32][33][34] that are known to exhibit an out-of-plane easy magnetization axis due to their strong interfacial anisotropy. As such, another example are metamagnetic/ferromagnetic bilayer structures [35][36][37][38][39][40], which can exhibit a very steep temperature (T) dependence of the magnetic coercivity (H C ), promoting them as good candidates for applications as recording media for heat assisted magnetic recording (HAMR) [41,42]. However, researchers have yet to find pathways to broadly tune the associated thermally activated transitions and by doing so achieve technological relevance.…”

Transmission of spin waves in ordered FeRh epitaxial thin films

“…Among a variety of magnetic materials, unique magnetic properties of B2-ordered FeRh alloys are currently being researched extensively, e.g., antiferromagnetic (AFM) -ferromagnetic (FM) phase transition [6][7][8][9][10][11][12][13][14][15][16][17] accompanied by a large reduction in the resistivity 14 , an isotropic volume expansion of ∼1% at the AFM-FM phase transition 13 , giant magneto-resistance 17 , laser driven ultrafast switching of the magnetic phases 18 , and exchange bias at AFM FeRh/ferromagnetic metal interface 19,20 . Recent work also has demonstrated electric field induced AFM-FM phase transition due to strain transfer effects [21][22][23][24] , spin polarized current induced AFM-FM phase transition in FeRh 25,26 , and AFM memristers 27,28 .…”