Pyroelectric contributions to piezoelectric hydrostatic Berlincourt method

Piezoelectric materials are used in many applications, at increasingly smaller scales. Methods of measuring their hydrostatic properties have been developed where the piezoelectric charge is produced as a result of a varying hydrostatic pressure generated within a sealed chamber. In this paper, the authors explore an anomalous generation of charge in thin laminar samples and show this is a result of the pyroelectric effect. The authors model the change in temperature in the sealed chamber caused by the adiabatic expansion of the gas and relate this to the observed generation of charge, using finite element modelling to investigate the temperature profile through the material. The implications of these results are relevant for the successful integration of piezoelectric thin and thick films into MEMS devices.