Structural, optical and electrical properties of multiferroic BiFe1-xNixO3 ceramic

Abstract

BiFe1−xNixO3 (x = 0.7, 0.8 and 0.9) polycrystalline ceramics are synthesized by a solid-state reaction, and their structural, absorption, leakage current and electrical properties are investigated. The X-ray diffraction measurements show that the lattice parameter values increase with increasing the substitution of Ni2+ ions for Fe3+ ions. The optical absorption spectra indicate that the band gap energy increases with increasing Ni2+ ions. Leakage currents are much decreased by about three orders of magnitude with increasing Ni ions. The J-E hysteresis was also investigated. Both real and imaginary dielectric constants are investigated as a function of both frequency and temperature. The room temperature dielectric measurement with a wide frequency range of 1 KHz–1 MHz reveals that the real and imaginary dielectric constants are decreased with increasing frequency of BiFe1−xNixO3 (x = 0.7, 0.8, 0.9) ceramics. The real and imaginary dielectric constants are found to be increased with temperature. The temperature dependence of ε′ and ε″ exhibits an anomaly which shifted to lower temperature with increasing Ni2+. The anomaly indicates the possible existence of spin-glass states with Ni2+ ion substitution in places of Fe3+ ions.