A 116-K SUPERCONDUCTOR WITH 1223-STRUCTURE - TIBASRCA2CU3O9-DELTA

A new superconducting thallium cuprate, TlBaSrCa2Cu3O9-delta, has been synthesized. The powder X-ray diffraction, electron diffraction and high resolution electron microscopy studies confirm that this oxide is isostructural with the "1223" TlBa2Ca2Cu3O9-delta and exhibits a high regularity in the layer stacking along the c-axis. The critical temperature of the as-synthesized sample (T(c) approximately 103 K) is improved by reducing annealing (T(c) approximately 116 K). The influence of the post-annealings, at low temperature, on the physical properties (T(c) and irreversibility line) is discussed.