Flux-grown PZN-PT Single Crystals for High-performance Piezo Devices

Large-size Pb(Zn_1/3Nb_2/3)O₃-PbTiO₃ (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 K^T ap 7000, d₃₃ ap 2800 pC/N and k₃₃ ges 0.92. For [011]-cut crystals, optimally poled PZN-7%PT single crystal exhibits very high transverse piezoelectric properties with d₃₂ ap -3800 pC/N, k32 > 0.90 and K^T ges 5000, while PZN-6%PT has d₃₂ ap -3000 pC/N and comparable k₃₂ and K^T 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.