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.