Rietveld Refinement of the Structure of TlSr2CaCu2O7 by X-Ray Powder Diffraction Data

Abstract
Single phase TlSr2CaCu2O7 was synthesized, and the crystal structure was refined from X-ray powder diffraction data using Rietveld analysis. The structure has single Tl-O sheets and tetragonal symmetry (a=3.7859 Å, c=12.104 Å) with space group P4/mmm, and is similar to TlBa2CaCu2O7 and Tl0.5Pb0.5Sr2CaCu2O7 (1212 type). Possible substitution of about 14% of Ca-sites with Tl ions was suggested.