Synthesis and Characterization of High Entropy Alloy Nitrides

This thesis focuses on a comparative investigation of thin films based on MoNbTaW high entropy alloy (HEA) and (MoNbTaW)N high entropy metal nitrides (HEN) deposited using High Power Impulse Magnetron Sputtering (HiPIMS) at varying nitrogen pressures. The study revealed a gradual transition in microstructure of the deposited films from a body centered cubic to a face centered cubic lattice with the incorporation of nitrogen. Moreover, the incorporation of insufficient nitrogen resulted in an amorphous microstructure. All samples demonstrated a remarkable thermal stability up to 900 °C. However, the HEN films exhibited cracking during annealing due to high residual stresses, while the HEA films experienced delamination in a few instances, but cracking was not observed. Based on the findings from this study, the HEN films exhibit promising potential as hard coatings due to their excellent thermal stability. Further investigations are warranted to evaluate their suitability as diffusion barriers in high-power electronic applications.