The photoacoustic effect at phase-transitions: its dependence on the thermal thickness of the sample

Abstract

The thermal properties that are the essential determinants of the PA-signal from a solid or a liquid are the density, the thermal conductivity and the specific heat. At a first-order phase-transition, the latent heat strongly influences the signal. It has been found experimentally that the amplitude runs through a minimum; the phase-angle as a function of temperature shows different patterns /1,2/.