Quantitative determination of anisotropic magnetoelectric coupling in BiFeO$_{3}$-CoFe$_{2}$O$_{4}$ nanostructures

TL;DR

This study quantitatively measures the anisotropic magnetoelectric coupling in BiFeO₃-CoFe₂O₄ nanostructures, revealing enhanced transverse magnetoelectric susceptibility due to strain effects and magnetic domain alignment.

Contribution

It provides the first quantitative analysis of anisotropic magnetoelectric susceptibilities in heteroepitaxial BiFeO₃-CoFe₂O₄ nanostructures, highlighting strain-induced effects.

Findings

Transverse MES up to ~60 mV/cm Oe, five times larger than longitudinal MES.

Enhanced transverse magnetostriction due to strain and domain alignment.

Asymmetric MES lineshapes indicating strain-induced magnetoelectric effects.

Abstract

The transverse and longitudinal magnetoelectric susceptibilities (MES) were quantitatively determined for (001) heteroepitaxial BiFeO$_{3}$-CoFe$_{2}$O$_{4}$ nanostructures. Both of these MES values were sharply enhanced at magnetic fields below 6 kOe and revealed asymmetric lineshapes with respect to the dc magnetic field, demonstrating the strain-induced magnetoelectric effect. The maximum transverse MES, which reached as high as $\sim$60 mV/cm Oe, was about five times larger than the longitudinal MES. This observation signifies that transverse magnetostriction of the CoFe$_{2}$O$_{4}$ nanopillars is enhanced more than the bulk value due to preferred magnetic domain alignment along the [001] direction coming from compressive, heteroepitaxial strain.