Electrical behavior of Pb(Zr0.52Ti0.48)0.5(Fe0.5Nb0.5)0.5O3 ceramics

Polycrystalline sample of Pb(Zr0.52Ti0.48)(0.5)(Fe0.5Nb0.5)(0.5)O-3 (PZTFN) ceramics was prepared by a high-temperature solid-state reaction technique. Preliminary X-ray diffraction analysis confirms the formation of single phase compound with tetragonal crystal structure. The dielectric behavior of the material was studied in a wide frequency (100 Hz-1 MHz) and temperature (30-500 degrees C) range. The relationship between dielectric constant epsilon(r) and temperature showed a single Curie transition temperature (T-c = 255 degrees C), with as large a epsilon(r) value as 4200 at T. A low value of dissipation factor (tan delta), as small as 0.04 up to temperature above than T-c (frequency f = 1 kHz), with good insulating properties made the sample for prospective applications in microwave dielectric components and high-power-density capacitors. The higher diffusivity (gamma similar to 1.6) value of the dielectric peak in the material indicates the greater disordering in the system. The signature of ac conductivity depending upon frequency and temperature exhibits the presence of different type of charge species. It is observed that oxygen vacancy plays an important role for high temperature conduction mechanism and dynamics of polarization of the system. (C) 2011 Elsevier B.V. All rights reserved.