Title :
DC features and RF losses of Nb-based superconducting thin films
Author :
Di Gioacchino, D. ; Fabbricatore, P. ; Frigerio, S. ; Gambardella, U. ; Musenich, R. ; Parodi, R. ; Paterno, G. ; Rizzo, S. ; Vaccarezza, C.
Author_Institution :
INFN Lab. Nazionali di Frascati, Rome, Italy
fDate :
3/1/1991 12:00:00 AM
Abstract :
Superconducting thin films of Nb, NbN, and NbZr have been realized in view of their application to superconducting accelerating cavities. The samples have been sputtered on different planar substrates, i.e., glass, sapphire, and copper. The electrical and superconducting features of the films have been measured in the temperature range of 300 K to 4.2 K and in the presence of a magnetic field of up to 5 T. The residual resistivity, critical temperatures Tc, and upper critical fields Hc2 of the films are reported. The expected RF properties are discussed. Measurements of the RF dissipation of Nb75Zr25 films sputtered on copper substrates have been performed in a cylindrical TE011 cavity. For Nb75 Zr25 thin films, the authors have measured the superconducting energy gap and the surface resistance in a cylindrical TE011 cavity in order to compare the experimental value to the theoretical BCS (Bardeen-Copper-Schrieffer) computation result
Keywords :
niobium; niobium alloys; niobium compounds; superconducting critical field; superconducting thin films; superconducting transition temperature; surface conductivity; type II superconductors; zirconium alloys; 4.2 to 300 K; DC features; Nb; Nb75Zr25; NbN; NbZr; RF dissipation; RF losses; critical temperatures; planar substrates; residual resistivity; sputtered; superconducting thin films; upper critical fields; Copper; Magnetic field measurement; Magnetic films; Niobium; Radio frequency; Superconducting films; Superconducting thin films; Temperature distribution; Temperature measurement; Zirconium;
Journal_Title :
Magnetics, IEEE Transactions on
