We have studied the characteristics of different metastable states in NbTi thin film deposited on sapphire substrate in a region very close to the transition temperature Tc, which was estimated to be about 7.6 K in our sample. Localized dissipative zones are induced (phase-slip centers (PSC) and hot spots (HS)) when a current pulse larger than the depairing critical (Ic) current is sent through the filament. These resistive zones appear after a delay time at zero voltage (transient superconductivity) that depends on the thermal cooling time of the material. A time-dependent Ginzburg–Landau (TDGL) theory developed by M. Tinkham allows to extract the gap relaxation time from the measured time delays at a temperature very close to Tc. Furthermore, it appears that, well below Tc, this relaxation time is dominated by the thermal equilibration time of the film on its substrate. In addition, the niobium-based material showed a clear evidence that PSC can be considered as precursors for hot spots.
Bibliographical noteFunding Information:
K.H, A.M, and H.B gratefully acknowledge the support of the King Fahd University of Petroleum and Minerals, Saudi Arabia, under the IN161052 DSR research group project.
© 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics