Photothermal reflectance microscopy : signal contrast in the case of thick and thin grain interfaces in solids

In this work a thick interface model is proposed in order to describe the photothermal signal perturbation introduced by grain interfaces. The validity of the model is discussed based upon photothermal reflectance microscopy results obtained on Fe sintered samples. A comparison with the thermal resistance model, which is valid only in the case of thin interfaces, is also presented