Low temperature impedance, modulus and conductivity studies of Pb0.8Bi0.2Fe0.6Nb0.4O3 multiferroic

A low temperature impedance and modulus spectroscopic study of Pb0.8Bi0.2Fe0.6Nb0.4O3 (PFN-BFO) multiferroic solid solution was reported in this paper. PFN-BFO solid solution was synthesized by single step solid state reaction method and the crystal structure was found to be monoclinic with Cm space group. The obtained lattice parameters from XRD: a = 5.6663(1) A, b = 5.6694(1) A, c = 4.0112(1) A and β = 90.038(1)°. The electrical properties (impedance and modulus) of PFN-BFO were investigated over a wide range of temperature (133 K – 293 K) and frequency (100 Hz– 5 MHz) by impedance spectroscopy technique. Impedance and modulus spectroscopy studies confirm the contributions to the conductivity from grains only and the relaxation is of non Debye type. The bulk resistance decreases with increase in temperature and exhibits negative temperature coefficient of resistance (NTCR) behaviour. The relaxation phenomena are found to be temperature dependent.