Photoacoustic measurement of the thermal diffusivity ofPb1−xSnxTe alloys

A simple open photoacoustic cell method is demonstrated for obtaining the thermal diffusivity of ${\mathrm{Pb}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Sn}}_{\mathrm{x}}$Te alloys. It is based upon the measurement of the acoustic signal as a function of the modulation frequency in the region where the sample is thermally thick. The dependence of the measured values of the thermal diffusivity as a function of the alloy composition is also discussed.