Structure, dielectric, and multiferroic properties of Bi0.85Nd0.15Fe0.98Zr0.02O3 in Ba and Ti co-doping

Multiferroic (1–x)Bi0.85Nd0.15Fe0.98Zr0.02O3– xBaTiO3 (x = 0, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4) ceramics were synthesized by the conventional solid-state reaction method. X-ray diffraction studies confirm the phase transition from rhombohedral structure to pseudocubic structure with the introduction of BaTiO3. The results of the refinement indicate that the BaTiO3 is successfully doped into the crystal lattice. The microstructure analysis shows that the average grain size increases with the introduction of BaTiO3. An increase in remnant polarization has been achieved at room temperature as the BaTiO3 concentration increase. A great reduction of about two orders of magnitude in the leakage current density is observed in x = 0.375 ceramic. The dielectric properties have been enhanced by the addition of BaTiO3, which is attributed to the reduction in Fe2+ ions and oxygen vacancies. Due to the grain effect and structure transition caused by the doping of BaTiO3, the magnetization reveals a slight decrease, while the coercive field of x = 0.325 (Hc = 1785.8 Oe) increased to 6.4 times that of the undoped ceramic.