Evaluation method of longitudinal and transverse piezoelectric d-coefficients for thin films

Abstract

The main idea of this research is to provide a distinctive solution for the measurement of both the longitudinal and the transverse piezoelectric d-coefficients. d(33) and d(31), of ferroelectric thin films and also thick films. In general, to get these two coefficients of thin films, two different measuring systems are required. Here, we propose the improved method for the evaluation of these two coefficients with single equipment and with the relatively convenient procedure. The two-step loading process of applying the both positive and the negative pressure has been designed to acquire the piezoelectric coefficients. These results have been calibrated for both the longitudinal and the transverse piezoelectric d-coefficients, d(33) and d(31), Of thin films. In the first stage of the experiments, we have obtained d(33) Of 108pC/N and d(31) Of 56.8pC/N for the PZT thin films.