Strain-mediated magnetoelectric coupling in BaTiO3-Co nanocomposite thin films

Abstract

The authors present a metal-ceramic type composite film in which Co particles with the mean size of 70 nm are uniformly dispersed in an insulating ferroelectric BaTiO3 (BTO) matrix. Transmission electron microscopy images revealed that the Co particle was tightly surrounded with the BTO matrix in atomic scales. The magnetostrictive strain-induced change in the relative dielectric permittivity was demonstrated by observing pronounced magnetodielectric effects under a static bias magnetic field. The present BTO-Co composite thin film also exhibited large dynamic magnetoelectric responses (160-170 mV/cm Oe at 50 kHz) at room temperature by virtue of a tight bonding between the two constituting piezoelectric and magnetostrictive phases. (C) 2008 American Institute of Physics.