M(B)-curves were experimentally investigated. Fishtail-effect (FE) was observed in MG YBa2Cu3O7−δ and YBa2Cu3−xAgxO7−δ (at x≈ 0.02) crystals in a wide temperature range 40 K <T< 75 K at the orientation of magnetic field H∥c. It was obtained that the influence of bulk pinning on FE is more effective at low temperatures while the influence of surface barriers is more effective at high temperatures. The value Hmax for Ag-doped crystals is larger than for a pure one that due to the presence of additional pinning centers, above all on silver atoms.
Cite
@article{arxiv.0902.3394,
title = {Evolution of Fishtail-effect with aging in pure and Ag-doped MG-YBCO},
author = {D. A. Lotnyk and R. V. Vovk and M. A. Obolenskii and A. A. Zavgorodniy and J. Kováč and M. Kaňuchová and M. Šefciková and V. Antal and P. Diko},
journal= {arXiv preprint arXiv:0902.3394},
year = {2009}
}