Abstract
Contributions to the irreversibility from the bulk and surface pinning are investigated in detail for an underdoped Bi-2212 single crystal using the Campbell method. The measured flux profile showed a linear flux distribution suggesting a uniform bulk shielding current without surface pinning, as the Bean model predicts, in the field-temperature region far below the irreversibility line. Getting close to the irreversibility line, the AC penetration depth became longer and might exceed the specimen size, because the critical current density approached zero. Hence, the obtained profile was different from exact one. However, the theoretical analysis using the theoretical model of Campbell shows that there is no contribution from the surface irreversibility in this specimen.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call