Magnetoelectric Coupling in epsilon-Fe2O3

TL;DR

This study demonstrates magnetoelectric coupling in epsilon-Fe2O3 nanoparticles, showing significant permittivity changes near magnetic phase transitions and under magnetic fields, indicating potential for multiferroic applications.

Contribution

First experimental evidence of magnetoelectric coupling in epsilon-Fe2O3 nanoparticles through dielectric and magnetic measurements.

Findings

30% change in permittivity at magnetic transition

0.3% increase in permittivity under 6 T magnetic field at 100 K

Magnetoelectric coupling observed near magnetic phase transition

Abstract

Nanoparticles of the ferrimagnetic epsilon-Fe2O3 oxide have been synthesized by sol-gel method. Here, we report on the measurements of the dielectric permittivity as a function of temperature, frequency and magnetic field. It is found that, coinciding with the transition from collinear ferrimagnetic ordering to an incommensurate magnetic state occurring at about 100 K, there is an abrupt change (about 30 %) of permittivity suggesting the existence of a magnetoelectric coupling in this material. Indeed, magnetic field dependent measurements at 100 K have revealed an increase of the permittivity by about 0.3 % in 6 T. Prospective advantages of epsilon-Fe2O3 as multiferroic material are discussed.