Search for satellite reflections and low-temperature study of the 1223 and 2212 Tl-Ba-Ca-Cu-O superconductors

The structures of the 1223 and 2212 phases of the T1-Ba-Ca-Cu-O system have been determined at 125 K. No satellite reflections were observed in extensive searches at both room and low temperature. The temperature dependence of the thermal parameters of the thallium atoms confirms the presence of a static disorder beyond that already incorporated in the refinements.