Enhancement of critical current density by confinement of vortices in Bi2Sr2CaCu2Ox single crystals and thin films

Abstract

Thin dc-sputtered Bi2Sr2CaCu2Ox films show very high values of the critical current density jc (jc≊1.7×107 A/cm2 at T=6 K and jc≊1×106 A/cm2 at T=60 K, H=0) which are at low temperature the same as for irradiated Bi-2212 single crystals. In the high temperature range jc of the thin films is enhanced over jc of as-grown and Kr-irradiated single crystals. The magnetically measured current-voltage characteristics E(j) and the pinning potential U(j) have been used to characterize the difference in the pinning regimes in single crystals and thin films.