Carbon diffusion in alumina from carbon and Ti2AlC thin films

Abstract

Carbon diffusion is observed in single crystal a-Al2O3 substrates from carbon and Ti2AlC thin filmssynthesized via pulsed cathodic arc deposition. Diffusion was found to occur at substratetemperatures of 570 C and above. The diffusion coefficient of carbon in a-Al2O3 is estimated to beof the order 3 1013 cm2/s for deposition temperatures in the 570–770 C range by examiningelastic recoil detection analysis (ERDA) elemental depth profiles. It is suggested that an appropriatediffusion barrier may be useful when depositing carbon containing thin films on a-Al2O3 substratesat high temperatures.