MECHANICAL AND STRUCTURAL-PROPERTIES OF NI-C FILMS OBTAINED BY RF-SPUTTERING

This work reports on the structural and mechanical properties of Ni-C films, deposited on silicon substrates by RF magnetron sputtering of a plasma-sprayed Ni-C target. X-ray diffraction was used to determine t he phase structure, while the atomic composition and the chemical stat es were given by X-ray photoelectron and Auger electron spectroscopies . The internal stress, Young's modulus, hardness and scratch resistanc e were investigated, as a function of the RF electric power. The micro structure and the mechanical properties were found to be governed by t he kinetic energy transferred to the growing film. In low energy condi tions. the Ni-C films behaved mechanically as diamond-like carbons, an d the microstructure coincided with that of an amorphous C-fcc Ni comp osite. Inversely, in high energy growth conditions, the films were com posed of dispersed Ni3C small crystallites in an amorphous Ni-C mixtur e. Such a microstructure was characterized by low mechanical propertie s. (C) 1998 Elsevier Science S.A.