Characterization of flux-grown PZN-PT single crystals for high-performance piezo devices

Abstract

Relaxor ferroelectric Pb(Zn1/3Nb2/3)O 3-xPbTiO3 (PZN-PT) and Pb(Mg1/3Nb 2/3)O3-PbTiO3 (PMN-PT) single crystals are the potential candidates for future high-performance piezoelectric devices due to their exceptionally high dielectric and piezoelectric properties. Characterization on flux-grown PZN-PT single crystals of different orientations revealed that PZN-(6-7)96PT single crystals show good homogeneity in dielectric and electromechanical properties and composition. When poled in [001] direction, these crystals exhibit high longitudinal-mode properties with dielectric constant (KT) ≈ 7000, piezoelectric coefficients (d33) ≈ 2800 pC/N, and electromechanical coupling factors (k33) ≥ 0.92. For [011]-cut crystals, optimally poled PZN-7%PT single crystal exhibits very high transverse-mode dielectric and piezoelectric properties with K T ≥ 5000, d32 ≈-3800 pC/N and k32 ≥ 0.90. [011]-poled PZN-6%PT has d32 ≈-3000 pC/N and comparable k32 and KT values. In comparison with melt-grown PMN-PT single crystals, flux-grown PZN-PT single crystals show good compositional homogeneity, superior and consistent dielectric and electromechanical properties, and higher depolarization temperatures (TDP). © 2007 IEEE.