AC-poled 100 kHz low-frequency Pb(Zn_1/3Nb_2/3)O₃-PbTiO₃ single-crystal vibrator with giant piezoelectric strain constant and improved usable temperature range

Abstract An alternating current poling (ACP)-induced dielectric and piezoelectric properties and their temperature dependence of [001] oriented Pb(Zn 1/3 Nb 2/3 )O 3 (PZN)-PbTiO 3 (PT) single crystals with 5.0 mm thickness vibrator have been investigated. At room temperature, the ACP single crystal vibrator with 100 kHz of resonant frequency showed dielectric constant ( ε 33 T / ε 0 ) of 7900, piezoelectric constants d 33 of 3300 pC N −1 , g 33 of 48 × 10 −3 Vm N −1 , and figure of merit FOM (product of d 33 and g 33 ) of 159 pm 2 N −1 , respectively. The piezoelectric properties of the ACP PZN-PT single crystal vibrator were stable up to a phase transition temperature ( T pc ) of 113 °C and are the highest reported to date for single crystals with a T pc of ≥100 °C. The acoustic impedance of the PZN-PT single crystal vibrator, which affects transmit/receive sensitivity, was as low as 24 MRayls which is 20% lower than Pb(Mg 1/3 Nb 2/3 )O 3 -PT single crystals.