STUDY OF GENERATING CAPACITY OF PIEZOCERAMIC ELEMENTS BASED ON LEAD ZIRCONATE-TITANATE WITH LOW TITANIUM CONTENT

Abstract

This article is devoted to PZT-based solid solutions as the basis of active elements for single-use pulsed energy sources. The article evaluates the generating ability of a piezoceramic material based on lead zirconate-titanate with a low titanium content (Zr/Ti 0,94/0,06 + 1 % Nb2O5) under its shock loading. In such materials, the pressureinduced (uniaxial, pulsed hydrostatic, or shock wave) phase transition occurs from the polar ferroelectric phase to the non-polar antiferroelectric phase. The released energy in this case is an order of magnitude higher than with the piezoelectric effect. A measure of the accumulation of electrical charge is the value of the residual polarization, which is proportional to the electrical energy released during the phase transition. In the course of the work, the main electrophysical parameters of the material under study were obtained: relative dielectric constant, dielectric loss tangent in weak fields, piezoelectric charge constant . A number of numerical values of the residual polarization of the material under study were obtained by several methods: thermal depolarization and shock loading; the accumulated energy density is calculated as the ratio of the residual polarization to two absolute dielectric constants. An assessment of the generating capacity of the material under study and a comparative analysis with the industrially produced piezoceramic material PZT-19 are carried out. It was found that the density of the accumulated energy of the material under study is two orders of magnitude higher than that of PZT-19. It is also worth noting that the pressure-induced phase transition from the ferroelectric to antiferroelectric phase for materials with a low titanium content occurs at much lower pressures than in materials located near the morphotropic boundary. This behavior is due to the fact that the energies of the states of the ferroelectric and antiferroelectric phases differ insignificantly; therefore, a relatively small external influence (pressure or electric field) is sufficient to violate the existing stability and transfer piezoceramics from one phase state to another. This fact has a positive effect on the generating ability of elements made of the material under study, since when exposed to high pre ssure, the electrical resistance of the piezoelectric ceramics decreases significantly, and a significant part of the electrical energy can be dissipated in the piezoelectric element itself.