High strain, 〈001〉 textured 0.675Pb(Mg _1/3Nb _2/3)O ₃-0.325PbTiO ₃ ceramics: Templated grain growth and piezoelectric properties

Lead magnesium niobate-lead titanate, 0.675Pb(Mg _1/3Nb _2/3)O ₃-0.325PbTiO ₃ (PMN-32.5PT) ceramics were textured (grainoriented) in the 〈100〉-crystallographic direction by the templated grain growth process. The textured PMN-32.5PT ceramics were produced by orienting {001}-SrTiO ₃ (ST) platelets (∼10 μm in diameter and ∼2-μm thickness) in a submicron PMN-32.5PT matrix. The templated growth of 〈 001〉-oriented PMN-32.5PT grains on the ST platelets resulted in textured ceramics with ∼70% Lotgering factor and >98% theoretical density. Unlike most lead-based ceramics, excess PbO was not needed for sintering or grain growth. Based on unipolar stain-field measurements at 0.2 Hz, the textured samples displayed >0.3% strain at 50 kV/cm. Low-field d ₃₃-coefficients of >1600 pC/N (<5 kV/cm) were measured directly from unipolar measurements. The low drive field d ₃₃-piezoelectric coefficient of the highly textured samples is two times greater than polycrystalline PMN-32.5PT.