Growth, structure, and mechanical properties of transition metal carbide superlattices

Superlattices of TiC/VC have been deposited on MgO(001) substrates by simultaneous direct current metal magnetron sputtering and C₆₀ evaporation in the temperature range 200–800 °C. Thin superlattices (approximately 1000 Å) deposited at 400 °C exhibited an epitaxial growth with abrupt interfaces while films deposited at 200 °C showed a partial loss of epitaxy. At 800 °C roughening by surface diffusion started to degrade the superlattices and introduced a columnar microstructure. A loss of epitaxy was observed for thicker (>7000 Å) superlattice films deposited at 400 °C. The results suggest that this observation is due to difficulties in depositing epitaxial VC.