Superconducting Properties of the System Tl1-xHgxBa2Ca2Cu3O8+δ

Superconductivity above 130 Ii can be sustained across the system TI1-xHgxBa2Ca2Cu3O8+δ with 0.1 ≤ x ≤ 1.0. Details of the synthesis process for these polycrystalline samples focus on controlling the oxygen content and achieving phase-pure samples to maximize the superconducting volume. The techniques of fabrication avoid many difficulties associated with the volatility of Hg in the pure (x = 1.0) Hg-1223 compound. Superconducting properties determined from magnetization data yield estimates of the intragranular critical current density, Jc which are comparable to values for YBa2Cu3O7. Maximum values of Jc occur for x = 0.3 and exceed 10^4 A/cm' at 77 K and in a field of 1 Tesla.