TUNGSTEN CARBIDE PREPARED BY REACTIVE DC MAGNETRON SPUTTERING

Thin films of tungsten carbides were prepared by reactive (Ar + C6H6) sputtering in a d.c. cylindrical magnetron, with a cathode of pure W, onto 0,5 mm thick substrates of glass, monocrystalline silicon, tantal um, stainless steel, and on gold and copper foils with a thickness of about 1 mu m. Samples deposited at room temperature were amorphous, wi th composition in a range from W2C to WC1-x, except of the samples dep osited upon Au or Cu foils which were nanocrystalline (with a grain si ze characteristic length of 2,9 nm). Amorphous WC1-x phase was stable up to approximate to 1470K. Microhardness of the amorphous W2C film wa s below the expected value; the obtained results can be explained by p ossible incorporation of free carbon and/or carbon-hydrogen fragments into the tungsten carbide layers.