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

Abstract

Single phase TlSr 2 CaCu 2 O 7 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 TlBa 2 CaCu 2 O 7 and Tl 0.5 Pb 0.5 Sr 2 CaCu 2 O 7 (1212 type). Possible substitution of about 14% of Ca-sites with Tl ions was suggested.