The application of the photopyroelectric method for measuring the thermal parameters of pyroelectric materials

Abstract

The photopyroelectric calorimetry, in the standard (back) configuration, is applied in order to measure the thermal parameters of some pyroelectric materials. It is demonstrated that the method is able to simultaneously measure the thermal diffusivity and effusivity of a pyroelectric material. The information is obtained via a frequency scan of the amplitude or the phase of the pyroelectric signal; the measurements need no calibration. A combined amplitude-phase procedure, at a single frequency, leads to the same results. In the mean time, if the thermal parameters of the pyroelectric sensor are known, one can get the thermal effusivity of a sample acting in the experimental cell as a substrate. Investigations and theoretical simulations were performed on a well known pyroelectric material, LiTaO3, with various liquid substrates.