STEM-X-EDS analysis of morphotropic PZT ceramics: Analysis of Zr/Ti + Zr values fluctuation depending on microstructure and synthesis route of powders

A TEM-EDS analysis technique is applied to estimate dopant incorporation and Zr/Zr + Ti fluctuation in morphotropic PZT ceramics starting from powders synthesized by two routes. A solid-state synthesis route leads to less reactive powders requiring severe conditions to reach full densification. The hydrothermal route leads to more reactive powders that can be fully densified at lower temperature. In addition, the influence of Ni addition was analyzed. Zr/Zr + Ti fluctuations were estimated by the standard deviation of concentrations carried out by chemical analyses. It was shown that there is no significant partitioning of Zr and Ti inside a grain or in the ceramic. Each PZT material appears to be homogenous with a constant value of standard deviation of Zr/Zr + Ti ratios. The obtained values depend mainly on the presence or not of Ni addition whatever the nature of the chosen synthesis route. Standard deviation values of Zr/Zr + Ti ratios appear to be in accordance with literature values estimated by high temperature X-ray diffraction broadening. Results are also discussed relatively to some piezoelectric properties and more particularly to the quality mechanical factor.