Effect of ball milling time on the magnetoelectric coupling effect of the multiferroic liquid CoFe 2 O 4 –Ba 0.8 Sr 0.2 TiO 3

In this thesis, CoFe 2 O 4 (CFO) and Ba 0.8 Sr 0.2 TiO 3 (BST) particles were prepared by chemical co-precipitation and sol–gel methods, respectively. On this basis, the particles were surface modified and then the CFO-BST composite liquid was prepared by adding CFO: BST = 1:1 to the insulating base solution. XRD results showed that pure phase CFO and BST particles were successfully prepared. The maximum dielectric constant and residual polarization intensity were obtained at low frequency (200 Hz) at 30 h. However, the relative rates of change of dielectric constant and ferroelectricity under the action of magnetic field were increasing and then decreasing. At 2 h, the maximum rate of change of magnetic dielectric response (3.15%) and the maximum rate of change of magnetoelectric response (256.4%) were obtained, meanwhile, a coupling coefficient of 8.34 V/(cm Oe) was obtained. This value is several orders of magnitude greater than that of conventional ceramics and promises new applications. Graphic abstract The structure, dielectric and magnetoelectric effect.