INVESTIGATION OF THE EFFECT OF IMPURITY PHASES OF THE FEEDSTOCK ON THE PROPERTIES OF FERROELECTRIC CERAMICS OF THE PZT SYSTEM

Abstract

In the process of mass production of ferroelectric materials, impurities of various types and concentrations are periodically observed in the feedstock. The aim of the study was to determine the effect of impurity phases present in the feedstock on the dielectric and electrophysical properties of ferroelectric ceramics. In this work, the basic raw materials components included in the lead zirconate - titanate system for the presence of impurity components were studied by spectral analysis. The results revealed a group of impurity phases (Sb, Na, Bi, K, Fe) of different concentrations. The model object of the study was an industrially produced ferroelectric material with a perovskite structure and the chemical formula Pb0,95Sr0,05(Zr0,53Ti0,47)O3 + 1% Nb2O5. The objective of the study was the dosed introduction of impurity alloying additives into the composition of the initial ferroelectric material in order to possibly change the final properties. The study established the relevance of the dosed introduction of K and Na impurities at a concentration of 1-2 % into the PZT system in order to reduce the values of relative permittivity by 40-45 %. The dependences of the formed ceramic structure on the introduced impurity alloying phases have been established by scanning electron microscopy. The regularities of the "type of impurity additive – microstructure – properties" have been established. As a result of the study, the effectiveness of dosed administration of impurity alloying additives K and Na in order to modify the properties of ferroelectric ceramics of the PZT system was confirmed. Such impurity alloying leads to an increase in the values of the specific voltage sensitivity (g33) to 34-37 mV·m/N. Ferroelectric materials of this format are of high practical interest for the creation of acoustic transducers operating in reception mode.