High resolution technique for measuring charge and polarization distributions in dielectrics by piezoelectrically induced pressure step waves (PPS)

Abstract

Our step wave technique, so far, has been discussed with respect to the investigation of already prepared samples. In some situations it is of interest to study the buildup of charge and polarization distributions during the poling procedure. This can be accomplished by inserting an additional insulating film, e.g. mylar between the conducting rubber electrode and the sample film. The insulating film acts as a series capacitor reducing the signal amplitude with no influence on the signal shape. Poling of the sample is possible by DC-current (voltage ) supply with a thin metal electrode at the insulating film evaporated on the face in sample contact. The same technique is used for measuring the electrostriction coefficient. In both cases quantitative evaluation additionally requires the measurement of the insulating film capacitance.