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Transport - and inductive critical current densities in superconducting MgB2

Marc Dhalle·Pierre Toulemonde·Concetta Beneduce·Nicolas Musolino·Michel Decroux·Rene Flukiger
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Abstract

The critical current density of four MgB2 samples was measured inductively and for one of them also by transport. Pure phased and dense bulk samples yield a critical current density which in value, as well as in its magnetic field and temperature dependence, is essentially the same as the intra-granular current density measured in a dispersed powder. Also the correspondence between the inductive and transport data indicates that the grain boundaries in the bulk samples are totally transparent for the current. The current-voltage relation becomes rapidly shallow in the vicinity of a depinning line, well below the second critical field. Between the depinning line and the second critical field the material is ohmic and shows a marked magneto-resisitivity, indicative of a flux-flow regime.

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Marc Dhalle, Pierre Toulemonde, Concetta Beneduce, Nicolas Musolino, Michel Decroux, Rene Flukiger. 2001-04-23. Transport - and inductive critical current densities in superconducting MgB2. https://doi.org/10.1016/s0921-4534(01)00940-6

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