Magnetization reversal and spin dynamics exchange in biased F/AF bilayers probed with complex permeability spectra

TL;DR

This paper investigates the spin dynamics and magnetization reversal in ferromagnetic/antiferromagnetic bilayers using complex permeability spectra across a broad frequency range, proposing a phenomenological model to explain the observed hysteretic resonance behavior.

Contribution

It introduces a phenomenological Landau-Lifshitz-based model for complex permeability in F/AF bilayers and compares experimental results with theoretical predictions.

Findings

Resonance frequencies exhibit hysteresis during magnetization.

The proposed model successfully describes the complex permeability spectra.

Experimental data aligns with theoretical predictions.

Abstract

The spin dynamics of the ferromagnetic pinned layer of ferro-antiferromagnetic coupled NiFe/MnNi bilayers is investigated in a broad frequency range (30 MHz-6 GHz). A phenomenological model based on the Landau-Lifshitz equation for the complex permeability of the F/AF bilayer is proposed. The experimental results are compared to theoretical predictions. We show that the resonance frequencies, measured during the magnetization, are likewise hysteretic.