Structural and Low Temperature Dielectric Studies on Pb_(0.8)Bi_(0.2)Fe_(0.6)Nb_(0.4)O_3 Multiferroic Solid Solution

摘要

In this paper the structural and low temperature dielectric properties of Pb_(0.8)Bi_(0.2)Fe_(0.6)Nb_(0.4)O_3 (PBFNO) multiferroic solid solution were reported. PBFNO multiferroic was synthesized by single step solid state reaction method. Calcination was carried out at 700 % 2hr with different sintering temperature (800 °C, 850 °C, 900 °C, 950 °C, 1000 °Cand 1050 °C for 1 hr) and time duration (800 °C for 1 to 5 hr). Single phase was confirmed through room temperature (RT) X-ray Diffraction (XRD). It was found that sintering carried out at 800°C/3 hr gives single phase. Rietveld refined lattice parameters using monoclinic structure are: a= 5.6663(1) A, b= 5.6694(1) A, c= 4.0112(1) A and p= 90.038(1)° with the average grain size as 2.987 μm. The dielectric properties studied over a wide range of frequency (100 Hz - 5 MHz) and temperature (133 K - 293 K). Dielectric constant and loss tangent exhibits frequency dispersion nature at low frequency region. AC conductivity increases with increase in temperature corresponds to negative temperature coefficient of resistance (NTCR) behaviour.