Dielectric properties of PLZT-x/65/35 (2≤x≤13) under mechanical stress, electric field and temperature loading

Pytel Pytel,Livinsh Livinsh,Suchanicz Suchanicz,Sternberg Sternberg

doi:10.5488/cmp.16.31706

Abstract

We investigated the effect of uniaxial pressure (0-1000 bars) applied parallely to the ac electric field on dielectric properties of PLZT-x/65/35 (2 \leqslant x \leqslant 13) ceramics. There was revealed a significant effect of the external stress on these properties. The application of uniaxial pressure leads to the change of the peak intensity of the electric permittivity (\varepsilon), of the frequency dispersion as well as of the dielectric hysteresis. The peak intensity $\varepsilon$ becomes diffused/sharpened and shifts to a higher/lower temperatures with increasing the pressure. It was concluded that the application of uniaxial pressure induces similar effects as increasing the Ti ion concentration in PZT system. We interpreted our results based on the domain switching processes under the action of combined electromechanical loading.

Highlights

Single crystals, ceramics, polymers and ceramic-polymer composites which show ferroelectric behavior are used in many applications in electronics and optics
PLZT-x/65/35 with a different content of lanthanum powders were acquired by two-stage co-precipitation method from mixed solution of inorganic salts ZrOCl2 · 8H2 O, TiCl4, La(NO2 )3 · 6H2 O and Pb(NO3 )2 well described in paper [5]
The energy dispersive X-ray spectrometer (EDS) analyses completed for individual grains in different compositions indicated a homogenous distribution of all elements in ceramics

Summary

Introduction

Ceramics, polymers and ceramic-polymer composites which show ferroelectric behavior are used in many applications in electronics and optics. Softening and hardening of ferroelectrics by acceptor and donor doping are the key tools to control their electrical and mechanical properties. The soft one have a higher permittivity, larger electrical losses, higher piezoelectric coefficient and are easy to polarize and depolarize. They can be used for applications requiring very high piezoelectric properties. The hard one have a lower permittivity, smaller electrical losses, lower piezoelectric coefficients and are more difficult to polarize and depolarize. They can be used for rugged applications [1]. Ferroelectrics could be modified by substitutions of Pb2+ ions in PZT ceramics by La2+ one (i.e. PLZT)

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