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

The 0.675Pb(Mg1/3Nb2/3)O-3-0.325PbTiO(3) (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 degreesC 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) d(33) coefficients in the [001], measured directly from unipolar strain-field measurements, were ∼1150 pC/N. This d(33) coefficient is 1.2-1.5 times greater than randomly oriented samples. The poled ε(max) and ε(rt) for a 0.9-textured PMN-32.5PT ceramic were 21 500 and 2450, respectively. Factors limiting further property improvements are discussed. (C) 2003 American Institute of Physics.