Magnetic Dynamics of a Multiferroic with an Antiferromagnetic Layer

TL;DR

This paper models how the shape of antiferromagnetic particles influences their resonance properties in multiferroic materials, providing theoretical insights into shape-induced effects at the AFM resonance frequency.

Contribution

It introduces a Lagrange function-based model to analyze shape effects on AFM resonance in multiferroics, addressing theoretical debates.

Findings

Shape affects AFM resonance frequency in multiferroics.

External magnetic fields modify resonance conditions.

Conditions for parametric resonance are identified.

Abstract

Shape effects in magnetic particles are widely studied, because of the ability of the shape and the size to control the parameters of a sample during its production. Experiments with nano-sized samples show that the shape can affect also the properties of antiferromagnetic (AFM) materials. However, the theoretical interpretation of these effects is under discussion. We propose a model to study the shape-induced effects in AFM particles at the AFM resonance frequency. The Lagrange function method is used to calculate the spectrum of resonance oscillations of the AFM vector in a synthetic multiferroic (piezoelectric + antiferromagnet). The influence of the specimen shape on the AFM resonance frequency in the presence of an external magnetic field is studied. Conditions for a resonance under the action of an external force or for a parametric resonance to arise in the magnetic subsystem are considered.