Growth and characterization of tungsten carbide nanowires by thermal annealing of sputter-deposited WCx films

Abstract

In this letter, the growth of dense W2C nanowires by a simple thermal annealing of sputter-deposited WCx films in nitrogen ambient is reported. Straight nanowires with a density of 250-260 mum(-2) and length/diameter in the range of 0.2-0.3 mum/13-15 nm were obtained from the 700degreesC-annealed samples, which exhibit good electron field emission characteristics with a typical turn-on field of about 1.7 V/mum. The self-catalytic growth of W2C nanowires is attributed to the formation of alpha-W2C phase caused by carbon depletion in the WCx films during thermal annealing. (C) 2004 American Institute of Physics.