Investigation of structural and dielectric properties of (La, Fe)-doped PZT ceramics

Abstract

Polycrystalline samples of iron doped lead lanthanum zirconium titanate (PLFZT) with a general formula Pb-0.9(La1-yFey)(0.1) (Zr0.55Ti0.45)(0.975)O-3, [y = 0.0,0.3,0.5,0.7] near the morphotropic phase boundary have been synthesized by a high-temperature, solid-state reaction technique. Preliminary X-ray structural study of the compounds show the formation of tetragonal structure. Detailed studies of dielectric constant (e) and tangent loss (tan 6) as a function of frequency (102 Hz to 10 kHz) at room temperature (RT) and temperature (RT-350 degrees C) at 10 kHz suggest that compounds undergo ferroelectric-paraelectric phase transition of diffuse type. The activation energy (Ea) of the samples was calculated from the plot of AC conductivity versus inverse of absolute temperature. The temperature dependence of resistivity shows that the compounds have negative temperature coefficient of resistance