Title :
Vortex solid-liquid phase transition, J/sub c/ limiting factor, and vortex pinning force in superconducting Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10//Ag tape
Author :
Qiang Li ; Wiesmann, H.J. ; Suenaga, M. ; Motowidlo, L. ; Haldar, P.
Author_Institution :
Brookhaven Nat. Lab., Upton, NY, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
We present our study of the vortex solid-liquid phase transition of superconducting Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10/ in the mixed state, based on our detailed transport measurements of a Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10//Ag tape (J/sub c//spl cong/2/spl times/10/sup 4/ A/cm/sup 2/ at 77 K and zero field) immersed in liquid neon (27 K) and in liquid oxygen (54 K-90 K) as a function of applied magnetic field up to 17 T. A comprehensive vortex phase diagram is obtained. We show that the vortex. Solid-liquid transition is the fundamental limiting factor for J/sub c/ in this tape at T/spl ges/27 K in magnetic field (except at very low field). In addition, the field-dependence of the flux pinning force in both solid and liquid regime is discussed.<>
Keywords :
bismuth compounds; calcium compounds; critical current density (superconductivity); flux pinning; high-temperature superconductors; mixed state; multifilamentary superconductors; silver; strontium compounds; superconducting tapes; 0 to 17 T; 27 K; 54 to 90 K; Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10/-Ag; Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10//Ag tape; critical current density limiting factor; field-dependence; mixed state; vortex phase diagram; vortex pinning force; vortex solid-liquid phase transition; Flux pinning; Force measurement; Magnetic field measurement; Magnetic fields; Magnetic liquids; Phase measurement; Solids; Superconducting films; Superconductivity; Temperature;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
