Magnetic microscopy and simulation of strain-mediated control of magnetization in Ni/PMN-PT nanostructures

TL;DR

This study demonstrates how strain-induced electric fields in Ni/PMN-PT nanostructures can control magnetization, combining experimental microscopy with micromagnetic simulations to understand the effects of strain and geometry.

Contribution

It introduces combined experimental and simulation approaches to analyze strain-mediated magnetization control in Ni/PMN-PT nanostructures, highlighting the importance of coupled micromagnetic-elastodynamic models.

Findings

Magnetization can be controlled via electric field-induced strain.

Coupled micromagnetic-elastodynamic simulations are more accurate.

Sample geometry influences magnetization response.

Abstract

Strain-mediated thin film multiferroics comprising piezoelectric/ferromagnetic heterostructures enable the electrical manipulation of magnetization with much greater efficiency than other methods; however, the investigation of nanostructures fabricated from these materials is limited. Here we characterize ferromagnetic Ni nanostructures grown on a ferroelectric PMN-PT substrate using scanning electron microscopy with polarization analysis (SEMPA) and micromagnetic simulations. The magnetization of the Ni nanostructures can be controlled with a combination of sample geometry and applied electric field, which strains the ferroelectric substrate and changes the magnetization via magnetoelastic coupling. We evaluate two types of simulations of ferromagnetic nanostructures on strained ferroelectric substrates: conventional micromagnetic simulations including a simple uniaxial strain, and coupled micromagnetic-elastodynamic simulations. Both simulations qualitatively capture the response of the magnetization changes produced by the applied strain, with the coupled solution providing more accurate representation.