Magnetoelectric coupling in ε-Fe₂O₃ nanoparticles

Abstract

Nanoparticles of the ferrimagnetic epsilon-Fe2O3 oxide have been synthesized\nby sol-gel method. Here, we report on the measurements of the dielectric\npermittivity as a function of temperature, frequency and magnetic field. It is\nfound that, coinciding with the transition from collinear ferrimagnetic\nordering to an incommensurate magnetic state occurring at about 100 K, there is\nan abrupt change (about 30 %) of permittivity suggesting the existence of a\nmagnetoelectric coupling in this material. Indeed, magnetic field dependent\nmeasurements at 100 K have revealed an increase of the permittivity by about\n0.3 % in 6 T. Prospective advantages of epsilon-Fe2O3 as multiferroic material\nare discussed.\n