QUANTUM-SIZE EFFECT OSCILLATIONS IN MULTI LAYERS MO SI/

Oscillating dependences of the kinetic and superconducting parameters on the superstructure period D are found on the multilayers Mo/Si with variable thicknesses or metallic layers (8-200 angstrom) and constant thickness (25 angstrom) of Si interlayers. The extrema positions on t he D-dependences of the transition temperature T(C), of the resistivit y rho(n), of the ratio rho300/rho(n) and of the critical field derivat ive dH(C perpendicular-to)/dT\T(C) are strictly periodical with the pe riod 35 angstrom. The oscillations discovered are explained in terms o r the quantum size effect observed previously only on the single thin films of metals and semimetals. The oscillation period 35 angstrom exc eeds the value expected proceeding from data existing for the electron ic spectrum of pure molibdenum. This fact is possibly due to the chang e or Mo electronic structure in disordered thin layers and to the infl uence of the coupling between metal layers. The coupling manifests its elf also in the 3D-2D crossover observed in the H(C parallel-to))(T) d ependences. Mo/Si multilayers can be two-dimensional and three-dimensi onal for different physical properties.