Effect of (Mn, F) and (Mg, F) co-doping on dielectric and piezoelectric properties of lead zirconate titanate ceramics

The influence of (Mn, F) and (Mg, F) dopants on the piezoelectric properties of lead zirconate titanate (PZT) ceramic compositions close to the morphotropic phase boundary is investigated. PZT ceramics are prepared by a chemical route based on co-precipitation of oxalates and hydroxides. The acceptor is incorporated into the B site of the materials and the fluorine ion is introduced into anionic sites. The d(33) coefficient, the mechanical quality factor Qm and other properties are measured. Scanning electron microscopy is used to determine the grain size of the materials. Electron spin resonance is used to determine the valency state of Mn in fluorinated PZT ceramics. In Mn doped PZT, the introduction of a fluorine ion makes the poling process easier and increases the piezoelectric coefficients whereas the fluorination of Mg doped PZT constantly leads to hard materials with a lower piezoelectric response. This study shows that (Mn, F) co-doping produces semihard materials with high piezoelectric coefficients. (C) 2002 American Institute of Physics.