The complex ac susceptibility of YBa2Cu3O 7 (YBCO) coated conductor and YBCO single crystal has been measured at 77 K as a function of field amplitude and frequency, from which the E(J) characteristic is deduced. It is shown that the E(J) in the single crystal obeys a power law in a large range above Ec= 1 μV/cm, indicating a flux creep mechanism, whereas for the coated conductor there appears a transition from flux creep to flux flow at E∼10Ec. The reported contactless technique may be conveniently used for the research and development of coated conductors. © 2004 American Institute of Physics.
|Journal||Applied Physics Letters|
|Publication status||Published - 6 Dec 2004|