Tunability of magnetoelectric properties in CoFe₂O₄–PbZr_0.52Ti_0.48O₃ multiferroic fluids with different ferroelectric particle sizes prepared by carbon templates

Multiferroic fluids are novel fluid-based multiferroic composites in which particles can change their magnetization/polarization direction with an external field. In this study, CoFe₂O₄–PbZr_0.52Ti_0.48O₃ (CFO-PZT) multiferroic fluids were prepared by the milling method, and the effects of PZT particle size on settlement stability and magnetoelectric properties were systematically investigated. Crystal structure analysis shows that pure-phase CFO and PZT particles were successfully prepared. The microscopic morphology analysis indicates that the PZT particle size decreases as the carbon template size increases. Settlement stability is better when the particle size is 1.36 ± 0.04 μm. As the particle size decreases, the dielectric constant first increases then decreases, and finally increases. The residual polarization intensity decreases with decreasing particle size, but the saturation polarization intensity first increases and then decreases. After the magnetic field is applied, dielectric characteristics and ferroelectric properties decrease, showing the “negative magnetoelectric effect”. When the particle size is 1.89 ± 0.04 μm, the CFO-PZT multiferroic fluid has the maximum magnetodielectric and magnetoelectric coupling coefficients of 3.36% and − 3.39 V/(cm·Oe), respectively. Therefore, multiferroic fluids are expected to broaden the application fields of multiferroic materials.