Structure analysis of Au-containing cuprate of Au<f>1+x</f>Ba2Ca2Cu<f>3−x</f>O9 (Au-1223)

Single crystals of Au<f>1+x</f>Ba2Ca2Cu<f>3−x</f>O9 (Au-1223) were grown at 6 GPa and 1325 °C. This phase is the third member of the Au-containing cuprate family of AuBa2Ca<f>n−1</f>Cu<f>n</f>O<f>2n+3</f> and shows a weak signal of superconductivity. The crystal structure was refined to R1 <f>(I>2σ(I))=0.0188</f> and <f>wR2=0.0485</f> with <f>F2</f> data. The Au-1223 phase crystallizes in the space group Pmmm (no. 47), <f>a=3.8119(1)</f> A˚, <f>b=3.8556(1)</f> A˚, <f>c=15.4431(5)</f> A˚, <f>Z=1</f>. Partial substitution of Au for Cu in the CuO2 planes was revealed. The Au incorporation to the conduction layers may be a reason for the suppression of superconductivity in Au-1223. [Copyright &y& Elsevier]