Semiconducting phase of amorphous carbon-nickel composite films

Abstract

Amorphous carbon-nickel composite films, which constitute a homogeneously mixed phase of carbon and 10% nickel, are prepared by UV pulsed laser ablation. From the low temperature conductivity study of these films, a nearly activated conduction followed by conductivity saturation below a temperature of 25K has been identified. This is very different from undoped diamond-like carbon (DLC) films. The presence of additional density of states at the Fermi level observed in these samples when compared with DLC films, is directly confirmed using valence band spectroscopy.