Cathodic arc co-deposition of highly oriented hexagonal Ti and Ti2AlC MAX phase thin films

Ti2AlC belongs to a family of ternary nanolaminate alloys known as the MAX phases, which exhibit a unique combination of metallic and ceramic properties. Here we report pulsed cathodic arc deposition of c axis normal oriented Ti2AlC thin films on α-Al2O3 (001) single crystal substrates heated to 900 °C, without an intentionally pre-deposited seed layer. Oriented hexagonal Ti is observed in some films and an in-plane epitaxial relationship between the α-Al2O3 (001) substrate, the hexagonal Ti and Ti2AlC MAX phase is observed. We observe formation of the Ti2AlC phase in all films despite variations in elemental composition. The electrical resistivity of our films was in the range 0.48-0.67 μΩ m, higher than other values found for Ti2AlC in the literature.