Simultaneous high-frequency measurement of direct and inverse transverse piezoelectric coefficients of thin films using longitudinal vibration.

A setup and approach for simultaneous measurement of the inverse and direct transverse piezoelectric coefficients of piezoelectric films was constructed. A longitudinal vibration mode resonator with a hydrothermally synthesized (K,Na)NbO 3 film deposited on a SrRuO 3 /SrTiO 3 substrate was investigated. The fabricated vibrator consists of two upper electrodes, one for actuation and the other for sensing. A driving voltage was applied to the actuator electrode to generate mechanical vibration at its resonance frequency. The vibration velocity was measured with a laser Doppler vibrometer, and the output current from the shorted sensing electrode was also measured to simultaneously evaluate the inverse and direct piezoelectric responses. The obtained inverse piezoelectric coefficient e 31 ̅ was −3.60 C/m2, while the direct piezoelectric coefficient e 31 ̅ was almost same at −3.69 C/m2. From these values, the inverse and direct piezoelectric coefficients e 31 , f were −4.93 and −5.05 C/m2, respectively. [Display omitted] • Measurement method establishment of the inverse and direct transverse piezoelectric coefficients for piezoelectric films simultaneously. • Use longitudinal vibration mode resonator using a hydrothermally synthesized (K,Na)NbO 3 film deposited on SrRuO 3 /SrTiO 3 substrate • Almost similar inverse and direct piezoelectric coefficients ( e 31 ̅) value of −3.60 and −3.69 C/m2, respectively. [ABSTRACT FROM AUTHOR]