Nucleation and growth of CVD α-Al2O3 on TixOy template

► Nucleation of α-Al2O3 on Ti4O7 template ► Transformation of Ti4O7 → Ti3O5 during deposition of Al2O3 ► Phase transformation results in formation of porosity. ► The Ti(C,N)-template interface is the weakest interface. ► Trace elements of Cl, Fe and Cr were detected.