The reflected electrons spectroscopy technique presented here has been introduced by Afanas'ev and further developed by V.P. Afanas`ev, S.D. Fedorovich, A.V. Lubenchenko in Surface Analysis Lab of the Moscow Power Engineering Institute (Technical University).

Authors would like to acknowledge the contribution of D. Naujoks , A. Pavolotsky, M. Lukashevsky, A. Barat.

The study of Nb/Al and Nb/Al-AlOx/Nb structures has been stimulated by interest expressed by Dr. A. Pavolotsky, Group for Advanced Receivers Development (Chalmers University of Technology), earlier, Cryoelectronics Lab (Moscow State University).

Recently, this activity has been supported by Swedish Royal Academy of Science.