Minimum critical current density of 105 A/cm2 at 77 K in the thin layer of Bi1.8Pb0.4Sr2.0Ca2.2Cu3.0Oy superconductor near the Ag in Ag-sheathed tapes

Magneto-optical Imaging of Transport Current Densities in Superconductors

“…Only a fraction of the avaiIable superconducting cross-section is effective in carrying current. confirming expectations from slicing [13][14][15] For example, the current is often seen to follow a few-micron wide strip close to the Ag interface, as has been inferred from earlier mono-filament slicing studies 113-151 and from magneto-optical imaging in mono-15.71 and multi-fdaments [SI. The interface regions are often seen to contain well-textured, phase-pure microstructure 117.181 which is favorable to high current flow.…”

Evolution of the transport critical current density and irreversibility field as a function of heat treatment and pressing pressure during processing of Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3Ox tapes

“…To understand what is happening at a fundamental level, it is also desirable to understand how the active cross-section is changing. This is a very challenging task, so far only accessible by experiments such as microslice 6,20 or MO imaging, [7][8][9] in which the local J c is probed on scales much smaller than the transport measurement. Unfortunately, it was not feasible to perform these experiments on these samples, although an extensive MO imaging experiment has been performed on a sample of the three heat treatment, two GPa tape.…”

Field percolation and high current density in 80/20 DyBa2Cu3O7 − x/Dy2BaCuO5 bulk magnetically textured composite ceramics

“…Also examination of the 211-123 interfaces could explain the strong magnetic field dependence of the intragrain critical current densities J Cg . Other studies have probed the role of superconducting layers or interfaces like in Bi-2223-Ag sheated tapes, [5] even in 2212 Bi-based single crystal [6] or in Hg compounds. [7][8] We recently studied a 2223-2212 mixture prepared by the glass route.…”