The onset of dissipation and of harmonic generation in response to an ac magnetic field of high temperature superconductors are used for the identification of the irreversibility line below which dissipation occurs due to flux motion in the sample. We demonstrate, however, that in the presence of a static magnetic field and for low amplitude ac fields, the penetration close to the onset may occur into the Campbell regime in which the vortex motion induced by the ac field occurs inside the pinning potential well.
|Number of pages||9|
|Journal||Physica A: Statistical Mechanics and its Applications|
|State||Published - 15 Nov 1993|
Bibliographical noteFunding Information:
We wish to thank M.V. Feigelman,V Geshkenbein,J . Gilchrist, C.J. van der Beek and V.M. Vinokur for illuminating discussions;S . Bouffard and F. Rullier-Albenque for their help in heavy ion irradiation. The work at Bar Ran is supportedi n part by the Ministry of Sciencea nd Technology and in part by the Ministry of Energy and Infrastructure. One of us (Y.W.) acknowledges financial support from the Levi Eshkol Foundation.