Structural, dielectric, and multiferroic properties of (Bi0.5K0.5)(Fe0.5Nb0.5)O3

A polycrystalline sample of (Bi0.5K0.5)(Fe0.5Nb0.5)O3 was prepared using a mixed oxide at 1000 °C. The preliminary structural analysis using X-ray diffraction data of the compound indicates the formation of a single-phase rhombohedral structure similar to that of parent BiFeO3. Microstructural and elemental analysis using a scanning electron micrograph and energy-dispersive X-ray spectroscopy, respectively, were carried out at room temperature with higher magnification exhibiting a uniform distribution of grains and stoichiometry. The appearance of hysteresis loops (P–E) confirms the existence of ferroelectricity of the sample with a high remnant polarization of (2Pr) 17.76 μCcm−2. Using impedance spectroscopy, the electrical properties of the material were investigated at a wide range of temperature (25–500 °C) and frequencies (1 kHz – 1 MHz) suggesting dielectric non-Debye-type relaxation in the material. The nature of the Nyquist plot (Z ′ ∼ Z ″ ) shows the dominance of the grain contribution in the im...