STRUCTURE OF SUPERCONDUCTING SINGLE-CRYSTALS OF 2201 THALLIUM CUPRATE (TL1.85CU0.15)BA2CUO6, TC=110 K

Single crystals of 2201 phase with various superconducting transition temperatures ranging from nonsuperconducting to 110 K have been obtained. An X-ray structural study of tetragonal single crystals with T(c) = 110 K, space group I4/mmm, a = 3.8686 (3 ), c = 23.259 (3) angstrom, has been carried out. We have found that thallium atoms are partially replaced by copper atoms. We have also found that Tl atoms and O (3) atoms linked with Tl are displaced from their symmetrical sites. A correlation between the structure and properties of Tl-2201 cuprate crystals has been established on the basis of our data and the data reported in the literature.