Evolution of Fishtail-effect with aging in pure and Ag-doped MG-YBCO

D. A. Lotnyk, R. V. Vovk, M. A. Obolenskii +6

$M(B)$-curves were experimentally investigated. Fishtail-effect (FE) was observed in MG YBa${}_2$Cu${}_3$O${}_{7-\delta }$ and YBa${}_2$Cu${}_{3-x}$Ag${}_x$O${}_{7-\delta }$ (at $x\approx$ 0.02) crystals i…