Abstract:
It is possible to substitute Bi in the superconducting BaPb0.75Bi0.25O3 by Sb or Te without destroying the superconductivity. With Sb, a continuous series of solid solutions BaPb0.75Bi0.25−ySbyO3 (0 ≤ y ≤ 0.25) exists, while with Te, perovskite BaPb0.75Bi0.25−yTeyO3 exists only upto y = 0.15. With increasing substitution by Sb or Te, Tc decreases continously in both the systems. Superconductivity with a maximum Tc of 8K is found in Ba0.9La0.1Pb0.9−yBiyTl0.1O3 for y = 0.25.