CONCENTRATION PROFILES IN LASER-DEPOSITED NI C AND W/C MULTILAYERS/

Experimental studies of concentration profiles in W/C and Ni/C multila yers prepared by pulsed laser deposition are compared with ballistic s imulations of the deposition process by means of the computer code TRI DYN. One part of the deposited particles possesses kinetic energies of about 100 eV and leads to a ballistic mixing of the deposited layers. As a consequence, diffuse interface concentration profiles arise and the concentrations within the individual layers depend on the layer th ickness. The concentration profiles can be highly asymmetric between a djacent interfaces as observed e.g. in W/C multilayers. Simulations pr edict that the interface width for the deposition of W onto C is up to 3.5, times larger than in the opposite case. Differences between simu lation results and HREM, AES, X-ray and XPS studies suggest that the r esulting interface concentration profiles are essentially influenced b y compound formation as well as by demixing of components occurring du ring deposition.