Improved dielectric and ferromagnetic properties of Fe-site substituted rhombohedral structured BiFeO3 ceramic

We prepared BiFe0.95(Ni0.5Ti0.5)0.05O3 by the conventional solid-state reaction method. X-ray diffraction along with the Rietveld-refinement revealed the existence of a rhombohedral R3c symmetry in BiFe0.95(Ni0.5Ti0.5)0.05O3. The dielectric permittivity was investigated over a wide range of temperatures at 1 kHz. During its evolution, an anomaly was observed at 520 K, which corresponds to TN (antiferromagnetic transition temperature). The prepared ceramic exhibited a considerable improvement in dielectric properties compared to pure BiFeO3. From the magnetization dependence at room temperature, BiFe0.95(Ni0.5Ti0.5)0.05O3 enhanced magnetization (Mr ≈ 0.026 emu/g) and reduced the coercive field (Hc ˜ 110 Oe) compared to BiFeO3. BiFe0.95(Ni0.5Ti0.5)0.05O3 ceramic is ferromagnetic with a cluster-glass state unlike the antiferromagnetic BiFeO3-based compounds. The Raman study confirmed the X ray diffraction analysis, the dielectric measurement and magnetic one.