In this work, the fabrication of nanocomposites with silicon nitride/oxide into the thermoelectric matrix of cobalt silicide is presented. The different concentrations of nano-Si₃N₄ were intentionally introduced by mechanical grinding while it was found that the nanocomposites also included SiO₂ phase at micro- as well as at nano-scale. The structural and morphological modifications of the materials were studied by powder X-ray Diffraction, Scanning Electron Microscopy and Transmission Electron Microscopy. The nanocomposites were studied in terms of Hall Effect, Seebeck coefficient, electrical and thermal conductivity. Emphasis is given on the lattice thermal conductivity that was analyzed based on Effective Medium Theory and the contribution of each phase is taken into account.
Keywords: Thermoelectricity; CoSi; Nanocomposite; Nano-Si(3)N(4); Nano-SiO(2); Thermal Conductivity; Effective Medium theory; Porosity.