EVOLUTION OF INTERFACE STRUCTURE IN NI-C MULTILAYERS DEPENDING ON ANNEALING TEMPERATURE - USE OF EMBEDDED CO SUBLAYERS-MARKERS

To verify the mechanism of epitaxial self-smoothing of interfaces in N i(Co)/C multilayers annealed at optimum temperature, Ni/C multilayers with embedded Co atoms-markers at a desired depth were studied. This d epth-resolving EXAFS technique shows that mixed interfaces are separat ed at first stages of annealing followed by the crystallization of met al layers at the higher temperatures. The temperature of the interface separation coincides very closely with the temperature observed for a maximum multilayer reflectivity. These results are well explained by the decomposition of the metal glass-like region with carbon excess at the interface, simultaneously with coherent growth of metal (111) and graphite layers. Further bulk crystallization of the metal layers lea ds to the enhancement of interface roughness, and hence to a drastic d ecrease in reflectivity.