Structural, dielectric and ferroelectric properties of La and Ni codoped BiFeO3

The codoped Bi1-xLaxFe1-yNiyO3 (x = 0.0, 0.1; y = 0.0, 0.05) samples are processed by solid-state reaction route in order to study structural, dielectric and ferroelectric properties. X-ray diffraction patterns of La/Ni doped samples have been performed using the rhombohedral (R3c) symmetry. Raman scattering measurement infers nine Raman active phonon modes. The substitution of Ni ion at Fe-site in BiFeO3 essentially changes the modes position i.e. all the modes are observed to shift at lower wave number. Frequency variation of the dielectric constant (e′) and dielectric loss (tanδ) has been investigated. It decreases with increasing frequency of the applied alternating field and become constant at high frequencies signifies substantial role of interfacial polarization. The remnant polarization and coercive field for BLFO, BFNO, BLFNO are 0.08, 0.03, 0.64 μC/cm2 and 0.24, 0.22, 0.25 kV/cm, respectively. La/Ni ion doping in BFO has successfully enhanced the polarization.