Direct J c measurements and trapped field profiles using an identical superconducting bulk
Abstract:We measured the trapped field profiles on a ∅45 mm GdBCO superconducting bulk plate of 2 mm thickness magnetised using pulsed field magnetisation (PFM), zero-field-cooled magnetisation (ZFC) and field-cooled magnetisation (FCM). The profiles were compared with the distribution of the absolute value of the critical current density (J c) estimated by the magnetisation measurements using small pieces cut from the bulk plate. The J c value was enhanced about 20% below the seed crystal compared with that in the growth sector regions (GSRs). The J c value was also slightly enhanced on the growth sector boundaries (GSBs). For a lower applied pulsed field than that for full magnetisation for PFM, a small amount of the magnetic flux was preferentially trapped at the lower J c region around the bulk periphery, which was not necessarily similar to that by ZFC. For a higher applied pulsed field, the magnetic flux was finally trapped below the seed crystal and at the GSBs.
Document Type: Research Article
Publication date: October 1, 2011