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

Large-size Pb(Zn
_1/3
Nb
_2/3
)O
₃
-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 K
^T
ap 7000, d
₃₃
ap 2800 pC/N and k
₃₃
ges 0.92. For [011]-cut crystals, optimally poled PZN-7%PT single crystal exhibits very high transverse piezoelectric properties with d
₃₂
ap -3800 pC/N, k32 > 0.90 and K
^T
ges 5000, while PZN-6%PT has d
₃₂
ap -3000 pC/N and comparable k
₃₂
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.