Enhanced dielectric and multiferroic properties in BaTiO3 doped Bi0.85Nd0.15Fe0.98Mn0.02O3 ceramics

The multiferroic ceramics of (1-x) Bi0.85Nd0.15Fe0.98Mn0.02O3-x BaTiO3 (x=0, 0.275, 0.3 and 0.325) were prepared by the conventional solid phase reaction. The crystal structure, microstructure, dielectric, ferroelectric and magnetic properties were systematically investigated. The X-ray diffraction pattern indicates that the structure of Bi0.85Nd0.15Fe0.98Mn0.02O3 is rhombohedral and the space group is R3c. Rietveld refinement shows that with the introduction of BaTiO3, the crystal structure of the material transformed from rhombohedral (R3c) to pseudo-cubic (P4mm). Scanning electron microscopy analysis shows that the average grain size decreases with the introduction of BaTiO3. Temperature dependence of the dielectric constant and the dielectric loss indicate that the introduction of BaTiO3 leads to ferroelectric relaxation. The dielectric constant and the dielectric loss are improved in sync. The leakage current density is reduced by about two orders of magnitude under the electric field of 15 kV/cm. The ferroelectricity and ferromagnetism are greatly improved after the addition of BaTiO3 seen from the polarization hysteresis (P-E) loops and the magnetization hysteresis (M-H) loops.