Dielectric and piezoelectric properties of modified lead titanate zirconate ceramics from 4.2 to 300 K

Abstract

The dielectric and piezoelectric properties (d-p properties) of four kinds of doped lead titanate zirconate piezoelectric ceramics (PZTs) have been measured from 4.2 to 300 K. The d-p properties of the materials converge with decreasing temperature down to liquid helium temperature, even though the properties have large differences at room temperatue. The values of mechanical and electrical quality factors,Q _m,Q _e, and of the frequency constant,N, of the materials increased at low temperature. It is evident from the freeze out inK′ and the associate temperature: frequency-dependent maxima in tan 5 that the relaxation processes including ferroelectric domain wall motion and thermal defect motion contribute to the d-p properties. The Navy type-III composition has a minimum temperature coefficient of d-p parameters and it is evident that PZT ceramics modified with Fe₂O₃ can provide good stability and also give the strongest piezoelectric response at liquid helium temperature.