An investigation of the properties of epitaxial chromium-substituted vanadium carbide thin films

• Epitaxial Cr-substituted vanadium carbide (V1-xCrx)2C thin films were deposited on c-axis sapphire by magnetron sputtering.
• Solid solutions were found for x up to ≈0.5 for a wide range of deposition temperatures.
• Surface friction was quite low, as long as the surface roughness remained below a critical value of about 2 nm.
• There was significant enhancement in corrosion resistance over that of V2C for even small amounts of Cr substitution (x∼0.1).

We report on the synthesis and physical properties of epitaxial Cr-substituted vanadium carbide (V1−xCrx)2C thin films deposited on c-axis sapphire by magnetron sputtering using a co-deposition technique. Solid solutions were found to form up to x ≈ 0.5 over a wide range of deposition temperatures. In general, it was found that surface roughness is dependent on the degree of crystallinity as well as the deposition temperature. However, the surface friction was remarkably low, as long as the surface roughness remained below a critical value of about 2 nm. Even for relatively small amounts of Cr (x ∼ 0.1), there was significantly enhanced corrosion resistance over that of V2C.