DETERMINATION OF THE CRITICAL CURRENT-DENSITY IN HTSC THIN-FILM MULTILAYERS

In this paper the limitations and perspectives of a simple remanent field technique for the determination of the critical current density (j(c)) in high-temperature superconductor (HTSC) thin films and in HTSC thin-film multilayers at 77 K were examined. As the comparison with resistive j(c) measurements on microbridges shows, j(c) values down to 10(4) A/cm2 can easily be measured with high accuracy. The method is nondestructive, fast, and inexpensive. It is especially suitable for j(c) measurements of double-sided coated substrates, where the determination of the individual j(c) values of both thin-film layers is possible.