FREE-ELECTRON DISTRIBUTION IN THIN-FILMS

In this paper we analyze the electron states in metallic films. The fi rst part of the paper is devoted to the study of the film where ion-io n interaction changes only in boundary layers. It was concluded that b ulk states always appear in such film. Surface states appear only if t he variation of the ion-ion interaction in the direction of the symmet ry breaking in the boundary layer are neutralized. If the conditions f or the creation of surface states are realized, one can obtain dense c urrents running along the film surface. In the second part of the pape r we study the film where translational symmetry is broken in the whol e volume. Symmetry breaking is treated as a perturbation. The perturba tion was homogenously spatially distributed in the vicinity of the fil m boundary, while the central part was unperturbed. The analysis of th e electron states in such a perturbed film has shown that the maximum of the electron density shift towards that part of the film where pote ntial wells of the ion-ion interaction are shallower. Electrons in thi s part of the film have comparatively high population and increased ch emical potential, which implies higher density of states. From the poi nt of view of the BCS theory, these electrons might have a higher crit ical temperature compared to the electrons in the unperturbed metallic matrix.