Dielectric and piezoelectric studies of Fe doped PLZT ceramics

Polycrystalline samples of Pb0.9(La1 − zFez)0.1(Zr0.65Ti0.35)0.975O3 [referred as PLFZT] (where z = 0.0, 0.3, 0.5 and 0.7) have been synthesized by a high-temperature solid-state reaction technique. X-ray diffraction analysis suggests the formation of single-phase compounds with tetragonal structure. The dielectric studies of the compounds as a function of temperature (from room temperature (RT) to 600 K) at a frequency 10 kHz show that the compounds undergo a phase transition of diffuse type. Diffusivity studies of the phase transition of these compounds provided its value between 1 and 2, indicating the variation of degree of disordering in the system. Measurement of dc resistivity (ρdc) as a function of temperature (RT to 600 K) at a constant biasing field dc 10 V/cm suggests that the compounds exhibit negative temperature coefficient of resistance (NTCR). The piezoelectric parameters as planar coupling coefficient, frequency constant and mechanical quality factor have been presented.