Enhanced dielectric and ferroelectric properties of Ba and Ti co-doped BiFeO3 multiferroic ceramics

• The structural phase transition with increasing Ti content was confirmed.
• The reduction of low frequency dispersion in dielectric constant with Ti content.
• With increasing Ti content the ferroelectricity was gradually improved.
• Variation of the ferroelectric hysteresis loop induced by magnetic polarization.

Multiferroic ceramics Bi0.8Ba0.2Fe1−xTixO3 with x = 0, 0.1 and 0.2 were prepared by using the conventional solid state reaction method. The structural, dielectric, ferroelectric and magnetic properties were investigated. The structure phase transition from rhombohedral to tetragonal with increasing the Ti substitution concentration was confirmed using X-ray diffraction. The reduction of low frequency dispersion in the dielectric constant and loss with an increase in the Ti content was observed. The ferroelectric measurements revealed that the leakage current is significantly suppressed with Ti substitution. Magnetic hysteresis loops showed a continuous decrease in magnetization with Ti substitution, which can be attributed to the collinear antiferromagnetic spin structure in tetragonal structure. In addition, a remarkable change in the polarization and ferroelectric loop area after poling the samples in the dc magnetic field indicates the presence of magnetoelectric coupling at room temperature.