Short-time piezoelectric measurements in ferroelectric thin films using a double-beam laser interferometer

An evolution of the double-beam laser interferometer used for piezoelectric measurements in ferroelectric thin films is reported. Measuring the d33 hysteresis of a ferroelectric material using lock-in technique with large time constants requires a varying bias field to be applied to the sample over a long period of time. This long-term application leads to electrical stress during the measurement. We present a measurement technique using a different source for the applied field and a varied method for averaging the interferometric response. The measurement time for a complete d33 hysteresis will be shortened down to several seconds. Also, the cycle frequency becomes comparable to electrical hysteresis measurements. Experimental results on quartz and Pb(Zr(X) ,Ti(12X))O3 are given to demonstrate the capabilities of the interferometer and the new measurement method. © 2003 American Institute of Physics. @DOI: 10.1063/1.1544415#