Flux-grown PZN-PT single crystals for high-performance piezo devices

Abstract

Large-size Pb(Zn1/3Nb2/3)O3-PbTiO 3 (PZN-PT) single crystals of different PT contents were successfully grown using an improved flux growth technique. Measurements made from samples of different orientation cuts revealed that PZN-(6-7)%PT single crystals exhibit exceptional dielectric and electromechanical properties. When poled in [001] direction, these crystals yield KT ≈ 7000, d33 ≈ 2800 pC/N and k33 ≥ 0.92. For [011]cut crystals, optimally poled PZN-7%PT single crystal exhibits very high transverse piezoelectric properties with d32 ≈ -3800 pC/N, k32 ≥ 0.90 and KT ≥ 5000, while PZN-6%PT has d32 ≈ -3000 pC/N and comparable k32 and KT values but a high overpoling field of >2.0 kV/mm. 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 depolarisation temperatures.