Magnetic, local ferroelectricity and magnetodielectric properties of NiFe2O4-poly (vinylidene-fluoride)-BaTiO3 composite film

Abstract

We report the magnetic, dielectric, and magnetoelctric properties of NiFe2O4-poly (vinylidene-fluoride)-BaTiO3 composite film. The coercive field (±2Hc∼344 Oe) and remnant magnetization (Mr-Q6-1 emu g-1) were observed at room temperature. The dielectric permittivity at room temperature (e RT∼281) was found to decrease with increase in frequency. The magnetocapacitance was found to be∼5.9% at an applied dc magnetic field of 8 kOe (frequency=∼1 kHz). Magnetoelectric coupling coefficient (δ\∼4-1mVcm-1 Oe-1) measured by dynamic method (at ac magnetic field=30 Oe) is observed higher (two times) than those reported for some materials. In addition, we have observed the image of ferroelectric domain using piezoelectric force microscopy at room temperature. Large magnetodielectric/magnetoelectric response in this composite is possibly a result of the effective mechanical interaction between NiFe2O4 and BaTiO3 through the polymer matrix.