Measurement of thermal diffusivity using deformation angle based on the photothermal displacement method

A new method of measuring the thermal diffusivity of solid material at room temperature using photothermal displacements is proposed. The influence of the parameters, such as radius and modulation frequency of the pump beam and the sample thickness, was studied. In previous works, thermal diffusivity was determined by the deformation angle and phase angle as the relative position between the heating and probe beams. In this study, however, we proposed the new analysis method based on position of real part of deformation angle with respect to the pump beam. From the zero-crossing position of real part of deformation angle with respect to the pump beam, the thermal diffusivity of the materials can be obtained. The experimental values for different values for different samples obtained by applying the new method are in good agreement with the literature values