Critical current and penetration depth in (Tl0.5Pb0.5)(YxCa1-x)Sr2Cu2O7- delta

Abstract

The authors report a series of Jc measurements made on (Tl0.5Pb0.5)(YxCa1-x)Sr2Cu2O7- delta , over a range of x. The results show a clear peak in intragrain Jc with x corresponding to the peak in Tc, but a continuous decrease in intergrain Jc. This lack of correspondence is unique amongst the doped materials they have studied. The behaviour of the London penetration depth with x has also been estimated. The data indicate an increase in lambda L across the range, but a coincident fall in the average particle radius makes this conclusion uncertain.