Europhys. Lett., 58 (3) , pp. 422-428 (2002)
Characteristic features of the temperature dependence of the surface impedance in polycrystalline samplesYu. A. Nefyodov1, M. R. Trunin1, A. F. Shevchun1, D. V. Shovkun1, N. N. Kolesnikov1, M. P. Kulakov1, A. Agliolo Gallitto2 and S. Fricano2
1 Institute of Solid State Physics - 142432 Chernogolovka, Moscow district, Russia
2 INFM, Unità di Palermo and Dipartimento di Scienze Fisiche e Astronomiche Via Archirafi 36, I-90123 Palermo, Italy
(Received 13 November 2001; accepted in final form 4 February 2002)
The real and imaginary parts of the surface impedance in polycrystalline samples of different density with the critical temperature are measured at the frequency of 9.4 and in the temperature range . The normal skin-effect condition at holds only for the samples of the highest density with roughness sizes not more than 0.1 . For such samples extrapolation of the linear at temperature dependences and results in values of the London penetration depth and residual surface resistance . In the entire temperature range the dependences and are well described by the modified two-fluid model.
74.25.Nf - Response to electromagnetic fields (nuclear magnetic resonance, surface impedance, etc.).
74.70.Ad - Metals; alloys and binary compounds (including A15, Laves phases, etc.).
© EDP Sciences 2002