Magnetoelectric properties of ME particulate composites

摘要

Magnetoelectric (ME) composites are biphasic materials consisting of piezoelectric and piezomagnetic materials as the participating constituents. These ME composites when placed under external magnetic field show electrical polarization (ME output). This ME coupling is mediated by mechanical stress. In the present study, we have synthesized particulate composites of Ni_0.8Cu_0.2Fe₂O₄ and Ba_0.8Sr_0.2TiO₃ using conventional ceramic method. The XRD identifications showed that the sintered ceramics retained the presence of distinct ferroelectric and ferrite phases. The dielectric constant was determined as a function of temperature (room temperature to 650 °C) at different test frequencies. The DC resistivity was studied as a function of temperature. The measured ME response, dielectric constant, and resistivity demonstrated strong dependence on the volume fraction of Ni_0.8Cu_0.2Fe₂O₄ in the composite. The ME voltage coefficient strongly depends on the resistivity of the composites.