Published online by Cambridge University Press: 10 January 2013
Accurate powder diffraction data for the superconducting phase TlBa2Ca2Cu3O9−δ have been obtained. This phase crystallizes in a tetragonal unit cell, with space group P4/mmm. Cell refinement of our material resulted in a tetragonal unit cell with a=3.8453(8)Å and c = 15.909(4)Å. These diffraction data improve on data currently present in the powder diffraction file. Our experimental data also agree with calculated diffraction patterns obtained from published atom positions.