A detailed study of the resistive transition of Nb.88Ti.12N films has been performed from 10 out to 50K to test the theory of superconducting fluctuations. A crucial prediction of this theory is a change in the temperature dependence of the resistance corresponding to a change in the ratio of the film thickness to the temperature-dependent coherence length from d/ξ(T) 3 to d/ξ(T) < 3. We believe that we have observed this transition. The value of Aslamazov-Larkin parameter obtained from the three-dimensional region (d/ξ 3) is about 1 3 the value computed from the normal sheet resistance of the film. A remarkable feature of the transition is that the superconducting fluctuations possibly affect the resistivity at temperatures as high as 33K.
Bibliographical noteFunding Information:
I Supported in part by the U.S. Atomic Energy Commission under and by U.S. Air Force Office of Scientific Research, Office of Aerospace $ Alfred P. Sloan Fellow