Piezoelectric photoacoustic detection of first- and second-order phase transitions

Abstract
A theoretical model which accounts for the photoacoustic amplitude and phase generated at first- and second-order phase transitions in solids by using a piezoelectric detection system is proposed. This model is based on a previously published approach to the study of phase transitions by using microphonic detection systems. Measurements of the photoacoustic signal on CsCuCl3 and (N(CH3)4)2CoCl4 are presented. The results obtained are discussed in the framework of the theory.