Influence of surface roughness and deposition order on exchange bias in bilayer structures NiFe/IrMn

Abstract

Using ferromagnetic resonance (FMR) method, magnetic properties of bilayer structures consisting of ferromagnetic (F, Ni 80 Fe 20 ) and antiferromagnetic (AF, Ir 25 Mn 75 ) layers with alternative order of F and AF deposition were studied. It was found that the surface roughness is larger for the samples with AF on the top of F layers. The influence of AF layer thickness on the surface roughness and exchange bias for different types of structures was discussed.

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“…In fact, the relationship between the exchange anisotropy behavior and the structure and morphology of the interface is well established [37][38][39][40][41][42]. The layer deposition order [39,40] as well as the surface roughness in NiFe/IrMn [40] and in NiFe/NiO [41] affect the exchange anisotropy value. The surface morphology and the exchange anisotropy were studied in NiFe/IrMn bilayer deposited on a flexible substrate [42].…”

“…Theoretical models have been proposed to describe the spins at the interface and to understand the origin of this particular anisotropy. Different aspects of the interface will be described in Section 4; including the relationship between the structure and morphology of the interface and the exchange anisotropy behaviour [37][38][39][40][41][42][43][44][45]. Also, the aligned and the off-aligned cases are considered [46][47][48][49][50][51].…”