Lead Zirconate‐Lead Titanate Piezoelectric Ceramics with Iron Oxide Additions

Abstract

An investigation of the effects of small additions of Fe 2 O 3 to lead zirconate‐lead titanate ceramics with compositions between 45 and 60 mol% lead zirconate has shown that, with 2 moles of PbO to balance each mole of Fe 2 O 3 , the solubility of Fe 2 O 3 was about 0.8 wt% in compositions near the tetragonal‐rhombohedra1 boundary. The dielectric constant and dissipation factor for both rhombohedra1 and tetragonal materials were decreased by addition of iron oxide, whereas the mechanical quality factor and frequency constant were increased. The dependence of the electromechanical properties on grain size was qualitatively similar for both undoped and iron oxide‐doped materials; the presence of iron oxide inhibited grain growth and lowered the limiting grain size below which the electromechanical properties change rapidly with grain size.