Title :
Flux pinning in NbTi/Nb multilayers
Author :
McCambridge, J.D. ; Rizzo, N.D. ; Ling, X.S. ; Wang, J.Q. ; Prober, D.E. ; Motowidlo, L.R. ; Zeitlin, B.A.
Author_Institution :
Dept. of Appl. Phys., Yale Univ., New Haven, CT, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
We made thin film multilayers of NbTi and Nb (d/sub NbTi/=20 nm and d/sub Nb//spl ap/3-9 nm). Samples were characterized by electrical transport measurements between 4.2 K and T/sub c/, in magnetic fields up to 6 T. We present J/sub c/ as a function of the device geometry and orientation of the field. For some multilayers, J/sub c/ had a large peak whose onset occurs near /spl sim/0.2 H/sub c2/. We suggest this peak effect is caused by a softening of the tilt modulus. Measured critical current densities at 4.2 K of 16 kA/mm/sup 2/ at 3 T and 8 kA/mm/sup 2/ at 5 T are among the highest achieved in the NbTi system.<>
Keywords :
critical current density (superconductivity); flux pinning; niobium; niobium alloys; superconducting critical field; superconducting thin films; titanium alloys; type II superconductors; 0 to 6 T; 20 nm; 3 to 9 nm; 4.2 to 9.5 K; NbTi-Nb; critical current density; critical field; field orientation; flux pinning; superconductors; thin film multilayers; Electric variables measurement; Flux pinning; Geometry; Magnetic field measurement; Magnetic multilayers; Niobium compounds; Nonhomogeneous media; Softening; Titanium compounds; Transistors;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
