Dielectric and piezoelectric properties of 〈001〉 fiber-textured 0.675Pb(Mg1/3Nb2/3)O3–0.325PbTiO3 ceramics

The 0.675Pb(Mg1/3Nb2/3)O3–0.325PbTiO3 (PMN–32.5PT) ceramic composition (with 1 wt. % excess PbO) was fiber textured in the 〈001〉 direction by the templated grain growth process using 5 vol % oriented {001}-BaTiO3 platelet crystals as the templates. The templated ceramics annealed at 1150 °C for 5 h attained texture fractions as high as 0.9. The fiber-textured samples showed an increase in the piezoelectric, electromechanical coupling, and compliance coefficients when poled and measured in the 〈001〉-textured direction. The low drive field (<5 kV/cm) d33 coefficients in the 〈001〉, measured directly from unipolar strain-field measurements, were ∼1150 pC/N. This d33 coefficient is 1.2–1.5 times greater than randomly oriented samples. The poled εmax and εrt for a 0.9-textured PMN–32.5PT ceramic were 21 500 and 2450, respectively. Factors limiting further property improvements are discussed.