A study on self-field distribution in Ag-sheathed (Bi,Pb)(2)Sr2Ca2Cu3Ox monofilamentary tape using a scanning Hall sensor magnetometry

Using a scanning Hall sensor magnetometry with an active area 50 mu m x 50 mu m, two-dimensional self-field distributions due to trapping currents, induced by a removal of external fields perpendicular to a sample surface, have been measured with 0.2 mm steps on the Ag-sheathed (Bi,Pb)(2)Sr2Ca2Cu3Ox monofilamentary tapes with J(c) values equal to 71 and 110 A/mm(2) (77 K, 0 T), The samples are fabricated by a rolling process with an intermediate sintering step, The measured profiles are nearly symmetric with respect to the tape center and mainly ascribed to the inter-grain current transport that flows in the whole part of superconductor through grain boundaries. The line distribution derived from the results suggests that the current transport along a length direction is higher than that along a width direction by about twice, The mechanical rolling for superconductor tape introduces the weak links and causes severe modulation in the magnetic profiles that is ascribed to the intra-grain current circulation restricted within the grains themselves, The experimental behavior is qualitatively explained by numerical calculations on the self-field distributions using the Biot-Savart law based on the electromagnetism.