The effect of the heating rate on the core morphology and transport Jc of (Pb,Bi)2223 superconducting tapes

Abstract

The heating rate is an important parameter during thermal processing as it influences the amount and homogeneity of the liquid phase available at the sintering temperature. We present preliminary results into the effects of different heating rates on the core characteristics and transport J c of (Pb,Bi)2223 tapes. Heating rates of 5, 20 and 40 °C h −1 have been studied for sintering temperatures of 840 °C. The phase formation in the tapes was studied throughout the thickness of the core using XRD analysis. For tapes heated at 20 and 40 °C h −1 it was found that there was an initial lag in the rate of formation of the (Pb,Bi)2223 phase. The self-field transport J c measurements revealed that the magnitude of the transport J c is influenced by the heating rate used. For this investigation tapes heated to 840 °C at 5 and 40 °C h −1 showed a reduction in the magnitude of the transport J c compared to those heated at 20 °C h −1.