IAM - Ceramic Materials and Technologies

Correlation between surface texture and chemical composition in undoped, hard, and soft piezoelectric PZT ceramics

  • Author: Hammer, M.; Monty, C.; Endriss, A.; Hoffmann, M. J.
  • Source: JOURNAL OF THE AMERICAN CERAMIC SOCIETY 81 (1998), 3, 721–724
  • Correlation between surface texture and chemical composition in undoped, hard, and soft piezoelectric PZT ceramics.

Abstract

The electrical and mechanical properties of piezoelectric lead zirconate titanate (PZT) ceramics are strongly influenced by domain-wall motion, which can be tailored via the substitution of ions within the perovskite structure, Different domain mobilities are achieved by lead and/or oxygen vacancies, according to the valency and ionic radius of the dopants, To quantify the surface near domain mobility, hard (silver-doped), soft (lanthanum-doped), and undoped PZT ceramics have been prepared, An applied mechanical stress after sintering causes texturing near the surface, because of the ferroelastic behavior of the 90 degrees domains, The texture is quantified via X-ray diffractometry (XRD) analysis of the tetragonal F-T(002)- and F-T(200)-peak intensities, using least-squares refinement with Gaussian profile functions, The samples are subsequently annealed to remove the surface texture and again characterized via XRD measurements, However, annealed samples still reveal a preferred domain orientation that can be removed only by a second annealing of the pulverized samples, A comparison of the tetragonal additive systems clearly reveals the greatest domain mobility for lanthanum-doped PZT ceramics, whereas the silver-doped and undoped samples have similar ferroelastic behavior, Furthermore, the surface texture of all the compositions is dependent on the applied mechanical stress and cannot be removed completely by heat treatment.