Magnetic relaxation in the "Bragg-glass" phase in BSCCO

Abstract : Magnetic relaxation in the Bragg-glass phase of overdoped Bi2Sr2CaCu2O8 crystals was investigated using time-resolved magneto-optical visualisation of the flux distribution. This has permitted us to extract the current-voltage characteristic, which can be well described by a power-law, although fits to a stretched exponential E ~ exp(- jc/j)µ with 0.3 < µ < 0.8 are passible at long times in excess of 100 g. © 2000 Elsevier Science B.V All rights reserved.