Keywords

The thermoelectric efficiency of a material is measured through the value of the so-called ZT (power factor which is defined in the refences [1, 2]). High ZT values in thermoelectric systems are obtained by a good knowledge of the materials involved in their fabrication. In this volume, we will summarize the thermoelectric properties of materials based on silicon compounds and those presently under study. We will show that the phase transformations and phase stabilities of new materials are still unknown, and it is a problem for the synthesis and use of the thermoelectric modules . Applying the modern concepts of thermodynamics, a study of the systems is presented taking as objective their use in materials. We will discuss the development of thermodynamic databases of such practical materials and show the importance of the microstructural evolution of the materials during processing and services for improving their knowledge. For this reason, in this volume, we will present some peculiarities of these materials in light of a phase diagram analysis and show finally how the CALPHAD method is necessary to study such multicomponent materials and to determine the best synthesis process (single crystal growth, powder metallurgy, etc.) [3].