MAGNETIC PENETRATION DEPTHS OF (BIPB)-2212 AND (TLPB)-1212 - UNIVERSAL CORRELATIONS REVISITED

A systematic study of the dependence of the critical temperature on th e superconducting carrier density, as measured by mu+SR, was carried o ut for a variety of cuprate oxides. We have shown that substitution of Pb for Bi and La for Sr result in well pinned vortex lattices in Bi2S r2CaCu2Ox, and studied (BiPb)-2212 from the underdoped to the slightly overdoped regime. We also found that TI-1212 samples, which have opti mal maximum T(c)=108 K, trace a separate line with parameters comparab le to overdoped TI-2223 at the maximum. These data, together with data on Y-124/247, Tl-2201 and other cuprates result in an larger set of ' 'universal correlations'' between T(c) and sigma(0) is-proportional-to n(s)/m for the high temperature superconductors.