Study of the inner structure and its changes upon annealing of Co/C and Ni/C
multilayers prepared by pulsed laser evaporation method

V.A.  Chernov , N.I.  Chkhalo , M.V.  Fedorchenko , S.V.  Mytnichenko , S.G.
Nikitenko

Boreskov Institute of Catalysis, Novosibirsk 630090, Russia
Budker Institute of Nuclear Physics, Novosibirsk 630090, Russia
Institute of Solid State Chemistry, Novosibirsk 630128, Russia

     The EXAFS (Extended X-ray Absorption Fine Structure), WAXS (Wide-
Angle X-ray Scattering) and  SAXS (Small-Angle X-ray Scattering)
methods were used to study the inner structure of Ni/C and Co/C
multilayers produced by the pulsed laser evaporation technology, as
well as, the structural changes occurred in the multilayers upon
annealing.
     As the metal film during its deposition is not thicker than about
2 nm it was found to have an amorphous structure. With further
thickening of the metal film it acquires a polycristalline nature, and
at its thickness over 5 nm it possess the properties of a bulk
material. It is followed by an increase in the boundary roughness from
0.3 to 0.55 nm. The thickness of the mixed metal - carbon layer was
found to be about 0.4 nm.
     It was shown that the improvement of the X-ray optical
characteristics of multilayers may be achieved at the optimal
annealing temperature (about 320 in degrees Celsium) corresponding to
the self-epitaxial catalytic resolution of mixed layers. The exceeding
of this temperature leads to the bulk crystallization of the metal and
increases drastically the boundary roughness.