engleski

Raman study of a-WC thin films

Tungsten carbide is often used coating material for protection against wear, erosion, and high temperature oxidation due to its high hardness and excellent thermal stability. Due to its high melting point (2870°C) a various techniques are usually employed for its deposition. We used DC magnetron sputtering of W in a hydrocarbon environment to produce WC crystalline phases at a lower deposition temperature in comparison with other techniques. Depositing nanocrystalline carbides in an amorphous carbon matrix has a promising applications. These composites blend the hardness and thermal stability of carbides with the low friction coefficient of a-C to create a superior coating. A series of films with different composition parameters were prepared, varying the substrate temperature, applied bias and gas mixture. Raman spectroscopy was used to study a-C phase as a function of the deposition parameters. All spectra of a-C present in the material consists of two peaks, one related to graphite mode (G-line) and another which is due to the disorder (D-line). It is shown that increase in substrate temperature and applied bias affects the a-C structure by varying the ratio between the two components.

tungsten carbide; Raman scattering; thin films

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