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Tunneleffekt an amorphen und stark gestörten Zinnschichten
Author(s) -
Strieder E.
Publication year - 1968
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.19684770103
Subject(s) - cryostat , copper , tin , materials science , amorphous solid , superconductivity , liquid helium , coupling (piping) , condensed matter physics , flux (metallurgy) , transition temperature , helium , atomic physics , composite material , metallurgy , physics , chemistry , crystallography
We have performed tunnelmeasurements on evaporated tin‐films with various amounts of copper added. The tunneljunctions were evaporated and cooled down to helium temperatures in situ in a metal‐cryostat. Tin‐copper‐films, which are condensed at low temperatures, are amorphous. They have critical temperatures from 7 °K to 3,5 °K depending on the content of copper. Tunnelmeasurements indicate that the high transition temperature belongs to a superconductor with strong coupling, whereas the lower critical temperature is characteristic of a weak coupling superconductor. Structures in tunnelcharacteristics and transition‐curves indicate that a film can have several energy‐gaps and that regions with strong and weak coupling can exist in the films. — Describing the metal‐cryostat we point out that one can reach temperatures below 1 °K with small pumping rates by diminishing the Hell film flux.