Effect of ball milling time on the magnetoelectric coupling effect of the multiferroic liquid CoFe2O4-Ba0.8Sr0.2TiO3

In this thesis, CoFe2O4 (CFO) and Ba0.8Sr0.2TiO3 (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.

Automated summary

In this study, CoFe2O4 (CFO) and Ba0.8Sr0.2TiO3 (BST) particles were prepared using chemical co-precipitation and sol-gel methods respectively. The particles were then surface modified and the CFO-BST composite liquid was prepared by adding CFO: BST = 1:1 to the insulating base solution. XRD results confirmed the successful synthesis of pure phase CFO and BST particles. The maximum dielectric constant and residual polarization intensity were observed at low frequency (200 Hz) after 30 hours. However, the rates of change of dielectric constant and ferroelectricity under the influence of a magnetic field showed an initial increase followed by a decrease. At 2 hours, the maximum rates of change of magnetic dielectric response (3.15%) and magnetoelectric response (256.4%) were obtained, along with a coupling coefficient of 8.34 V/(cm Oe), which is several orders of magnitude higher than that of conventional ceramics, indicating potential applications.