ABSTRACT
This chapter discusses the methods involving thermal waves for the characterization of thermal conductivity or diffusivity of crystalline and amorphous nanostructured materials. It analyzes the influence of the temporal characteristic of the exciting heat source on the temperature evolution within the sample. The chapter overviews the application of electro thermal techniques for the evaluation of in-plane and cross-plane thermal conductivities of anisotropic systems. It demonstrates the use of photo thermal and photo acoustic techniques as powerful tools for the study of crystalline/amorphous materials. Thermal wave techniques are based on the exploitation of frequency-dependency of the amplitude and phase of the ac-component of the temperature. The comparison between 2D analytical and numerical simulations showed the validity of the method for the determination of cross-plane thermal properties of silicon thin films. The photo thermal and photo acoustic techniques for the study of the thermal properties of the crystalline/amorphous nanostructured material were discussed.
