AC loss and critical current density in Bi-2223 tapes with oxide additives and reinforced Ag sheaths

Abstract

A series of measurements have been conducted on the field and temperature dependent AC susceptibility (ACS) of Bi-2223 based superconducting tapes with Ag sheath of different degrees of hardness and various oxide additives (SrCO 3 and BaZrO 3) in the core materials. The applied AC field was aligned perpendicular to the tape surface, i.e. along the c crystallographic axes. The analysis of these data based on the strip model shows that SrCO 3 additive does not give rise to meaningful changes in the AC loss density ( q) and current density ( J c) while BaZrO 3 additive appears to lower q and J c considerably, especially at lower temperature. A reversed trend of changes in q and J c is exhibited by reinforcement of the Ag sheath.