Flux creep associated with bulk pinning and edge barriers in BSCCO-2212 single crystals
L F Cohen; J T Totty; G K Perkins; R A Doyle; K Kadowaki
Журнал:
Superconductor Science and Technology
Дата:
1997-04-01
Аннотация:
We have examined the flux creep behaviour in high-quality BSCCO-2212 single crystals by dynamic relaxation of the global magnetization using a vibrating-sample magnetometer. The irreversible magnetization is attributed to bulk pinning at low temperatures and to edge barriers at high temperatures. The increase of current at the anomalous `arrowhead' feature is related to the penetration of a Bean-type profile through the sample at a field . We show that at flux creep is enhanced. The fast-creep regime survives over a narrow field range up to a field , associated with the irreversibility line of the bulk pinning. Apart from the temperatures and fields where the arrowhead is observed, the creep rate has a similar normalized field dependence at all temperatures.
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