The Effect of SI and Y Additives on the Phase Stability of AI2O3 Thin Films

The goal of this thesis is to understand the atomistic mechanisms governing the structure evolution to control or affect phase formation and stability of alumina thin films deposited by filtered cathodic arc technique. The thesis is, therefore, subdivided into five chapters:A state of the art review is provided in Chapter 2. The review focuses on the polymorphism of alumina and the synthesis pathways for the different alumina polymorphs. Furthermore, it includes a summary of the current studies on the effect of additives on the stability of the metastable alumina phases with focus on the additives Si and Y. Chapter 3 describes the experimental and theoretical methods of research used within this study. Chapter 4 contains the experimental and theoretical studies of the effect of Si and Y additives on the high temperature stability of metastable gamma-Al2O3. Chapter 5 concludes the thesis and future research directions and perspectives are proposed in Chapter 6.