Tunable dielectric behaviors of magnetic field of PZT5/NiFe2O4 ceramic particle magnetoelectric composites at room temperature

• Mechanical mixing PZT/NFO ceramic particle composites were fabricated.
• Dielectric constant and complex impedance spectra were changed by 1 T field.
• MC and ML were related not to MR effect but to piezoelectric effect of the ferrite.

(1−x)PZT5/xNiFe2O4 (x = 0, 0.2, 0.3, 0.4, 0.5 and 1, abb. PZT/NFO) ceramic particle composites were fabricated of commercial PZT5 powder and self-fabricated NiFe2O4 by solid-state sintering at 1150 °C for 2 h. The formation of cubic spinel structure of ferrite phase and cubic perovskite structure of ferroelectric phase in the composites were confirmed by X-ray diffraction studies besides slight peaks of pyrochlore phase. The formation of pyrochlore phase could be restrained by increasing magnetic content and the ferroelectric behaviors of the composite were properly promoted at x = 0.2. On the other hand, remanant polarization (Pr) of PZT/NFO composites monotonously increased according to the adding content of PZT5 except for x = 0.2. Vice verse, ferromagnetic properties would be dominant with increasing NiFe2O4 phase. The direct magnetic field (Hdc) and ac electric field (Eac) were applied to the composites simultaneously for magnetocapacitance behaviors measurement. As a result, the self-modulation of dielectric and impedance were found for PZT/NFO composites. More interestingly, the magnetocapacitance of the composite probably was not related to the magnetoresistance as reported a lot but to the piezomagnetoeffects as expected. The PZT/NFO ceramic particle composites should be prospectively applied in multistate memories and else fields.