Sn Substitution of TlBaCaCuO Superconductors

In order to study how the Sn substitution for Tl changes the superconducting properties of the TlBaCaCuO compound, we have prepared samples with Sn in place of Tl by solid state reactions. Measurements of resistance and magnetic susceptibility show that partial substitution of Tl with Sn is helpful to form the superconducting 2223 phase (for T1:Ba:Ca:Cu). It has been found that samples mainly contain tetragonal phase 2223, but there also exist a few additional maxed phases like 1223, 1234 and nonsuperconducting phase BaSnO₃.