Europhys. Lett., 59 (2) , pp. 272-276 (2002)
Evidence for two-dimensional nucleation of superconductivity inA. S. Sidorenko1, 2, L. R. Tagirov1, 3, A. N. Rossolenko4, V. V. Ryazanov4, M. Klemm1 and R. Tidecks1
1 Institut für Physik, Universität Augsburg 86159 Augsburg, Germany
2 Institute of Applied Physics - 2028 Kishinev, Moldova
3 Kazan State University - 420008 Kazan, Russia
4 Institute of Solid State Physics - 142432 Chernogolovka, Russia
(Received 3 December 2001; accepted in final form 23 April 2002)
According to the crystal structure of and band structure calculations quasi-two-dimensional (2D) boron planes are responsible for the superconductivity. We report on critical fields and resistance measurements of 30 thick films grown on single crystalline substrate. A linear temperature dependence of the parallel and perpendicular upper critical fields indicates a 3D-like penetration of magnetic field into the sample. Resistivity measurements, in contrast, yield a temperature dependence of fluctuation conductivity above which agrees with the Aslamazov-Larkin theory of fluctuations in 2D superconductors. We consider this finding as an experimental evidence of two-dimensional nucleation of superconductivity in .
74.62.Bf - Effects of material synthesis, crystal structure, and chemical composition.
74.70.Ad - Metals; alloys and binary compounds (including A15, Laves phases, etc.).
74.76.-w - Superconducting films.
© EDP Sciences 2002