Dielectric and electromechanical properties of chemically modified PMN-PT-BT ceramics

A particulate coating process incorporating small amounts of several additi ves such as titanium, zinc, barium, strontium and iron was used to modify t he composition and resultant dielectric and electromechanical properties of a commercially available 0.96(0.91Pb(Mg1/3Nb2/3)O-3. 0.09PbTiO(3)). 0.04Ba TiO(3). This method led to intimate mixing of the additives at the nanoscal e without an additional ball-mixing process. Low- and high-field characteri stics including dielectric properties, induced strain and polarization, and associated hystereses were evaluated for the samples sintered at 1200 degr ees C for 4 h. All properties were found to depend on the chemical additive s and temperature. Specifically, the addition of small quantities of titani um and barium tended to increase strain and Q(eff) while maintaining a low dielectric constant which is a promising result for room temperature transd ucer applications. The addition of titanium with zinc or iron raised dielec tric constant, strain, and polarization with significant increases in the t emperature of maximum permittivity, On the other hand, the electromechanica l properties of the samples containing barium or zinc with titanium did not exhibit a transition to piezoelectric behavior at the temperature expected from the dielectric measurements.