Title :
Bulk, surface and shape contributions to critical current density in as-grown BSCCO-2212 single crystals. Part A-equilibrium behavior
Author :
Doyle, T.B. ; Labusch, R.
Author_Institution :
Sch. of Pure & Appl. Phys., Univ. of the Natal, Durban, South Africa
fDate :
6/1/2003 12:00:00 AM
Abstract :
A theoretical treatment for the prediction of the magnetization behavior, and hence also the critical current density, in a Type II superconductor of arbitrary shape is briefly reviewed. The treatment, which allows for the inclusion of explicit expressions for the constitutive equilibrium Brev (H) relation, bulk vortex pinning and surface surface-barrier effects, is self-consistently applied to magnetization isotherms for as-grown, single-crystal BSCCO-2212 specimens with platelet, disc, and ´prism´ geometry. In this part of the work the treatment is used to obtain Brev (H) and Hc1 (T) for this material, with the applied field, Ho, directed along the crystalline c-axis (specimen minor axis). In Part B (following paper) calculated normalized M(Ho/Hc1)/Hc1 curves are fitted to the normalized experimental magnetization isotherms for each specimen geometry to obtain the bulk critical current, Jc (B,T), behavior and the relative contributions to the magnetization isotherms from vortex pinning, specimen shape, and surface-barrier effects.
Keywords :
bismuth compounds; calcium compounds; critical current density (superconductivity); flux pinning; high-temperature superconductors; magnetisation; strontium compounds; BSCCO-2212 crystals; Bi2Sr2CaCu2O; Type II superconductor; critical current density; magnetization; surface surface-barrier effects; vortex pinning; Critical current density; Crystalline materials; Crystallization; Crystals; Geometry; Magnetic materials; Magnetization; Shape; Surface treatment; Type II superconductors;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.812117