VERTICALLY STACKED (NB SI)ASTERISK-10 JOSEPHSON-JUNCTION/

We report on ''Josephson superlattice'' - a stack of junctions consist ing of a multilayer [Nb(7nm)/Si(2nm)]10 deposited by dc sputtering. T he silicon barriers are amorphous and Nb sublayers are polycrystalline . The stacked junctions exhibit both ac and dc Josephson effects. In t he I-C(B) diffraction pattern there is an extra periodicity of about 2 -3 G in addition to larger period of about 21 G. The shape of I-C(B) c urve resembles the characteristics obtained on two JJs placed close to each other and connected in parallel. The possible explanation of thi s fine structure of the interference pattern is shortly discussed.