Microstructure and Properties of Cr 2 O 3 ‐Doped Ternary Lead Zirconate Titanate Ceramics

The effects of Cr 2 O 3 doping (0 to 0.6 wt%) on the microstructure and electrical properties of ternary Pb 0.97 Sr 0.03 ‐ [Zr 0.458 Ti 0.452 (Mn 1/3 Nb 2/3 ) 0.09 ]O 3 piezoelectric ceramics have been studied. Abnormal grain growth (grain sizes of 2.8 to 28.5 μm) and densification (porosities of 2% to 12%) are found, and the tetragonality c/a nearly keeps constant wherease c and a slightly decrease in the doping range. The results for the temperature dependence of electric conductivity and the dielectric constant show that electric conductivity increase continuously over 0.1 wt% content, activation energies are all close to 0.92 eV in the paraelectric state, and the Curie temperature T c decreases with increasing doping content. Minor additives of ≤0.1 wt% improve the dielectric and piezoelectric properties, but with more additives of ≥0.4 wt% electrical properties appear to deteriorate. Thus, these phenomena can be ascribed mainly to anomalous developed microstructure.