Electrical properties of Pb(Mg 1/3Nb 2/3)O 3–PbTiO 3 ceramics modified with WO 3

Abstract

Ferroelectrics 0.67Pb (Mg 1/3Nb 2/3)O 3–0.33PbTiO 3 (PMN–PT) + x mol% WO 3 ( x=0.1, 0.5, 1, 2) were prepared by columbite precursor method. Electrical properties of WO 3-modified ferroelectrics were investigated. X-ray diffraction (XRD) was used to identify crystal structure, and pyrochlore phase were observed in 0.67Pb (Mg 1/3Nb 2/3)O 3–0.33PbTiO 3+2 mol% WO 3. Dielectric peak temperature decreased with WO 3 doping, indicating that W 6+ incorporated into PMN–PT lattice. Lattice constant, pyrochlore phase and grain size contribute to the variation of K max. Both piezoelectric constant ( d 33) and electromechanical coupling factors ( k p) were enhanced by doping 0.1 mol% WO 3, which results from the introduction of “soft” characteristics into PMN–PT, while further WO 3 addition was detrimental. We consider that the two factors, introduction of “soft” characteristics and the formation of pyrochlore phase, appear to act together to cause the variation of piezoelectric properties of 0.67PMN–0.33PT ceramics doping with WO 3.