Materials Research Bulletin, Vol.46, No.12, 2527-2530, 2011
A quaternary lead based perovskite structured materials with diffuse phase transition behavior
A lead based quaternary compound composed of 0.25(PbZr(0.52)Ti(0.48)O(3)) + 0.25(PbFe(0.5)Ta(0.5)O(3)) + 0.25 (PbF(0.67)W(0.33)O(3))+ 0.25(PbFe(0.5)Nb(0.5)O(3)) - (PZT-PFT-PFW-PFN) was synthesized by conventional solid-state reaction techniques. It showed moderate high dielectric constant, low dielectric loss, and two diffuse phase transitions, one below the room temperature similar to 261 K and other above similar to 410 K. X-ray diffraction (XRD) patterns revealed a tetragonal crystal structure at room temperature where as scanning electron micrograph (SEM) indicates inhomogeneous surface with an average grain size of 500 nm-3 mu m. Well saturated ferroelectric hysteresis loops with good saturation polarization (spontaneous polarization, P(s) similar to 30.68 mu C/cm(2)) were observed. Temperature-dependent ac conductivity displayed low conductivity with kink in spectra near the phase transition. In continuing search for developing new ferroelectric materials, in the present study we report stoichiometric compositions of complex perovskite ceramic materials: (PZT-PFT-PFW-PFN) with diffuse phase transition behavior. The crystal structure, dielectric properties, and ferroelectric properties were characterized by XRD, SEM, dielectric spectroscopy, and polarization. 1/epsilon versus (T) plots revealed diffuse relaxor phase transition (DPT) behavior. The compositional variation on the phase transition temperature, dielectric constant, and ferroelectric to paraelectric phase transitions are discussed. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords:Ceramics;Electrical properties