Published online by Cambridge University Press: 14 April 2005
The substitution sites of Pb and Dy dopants in the cuprate-type high temperature superconductor Bi2Sr2Ca1Cu2O $_{8+\delta}$ are determined by a direct comparison of the angle-scanned X-ray photoelectron diffraction (XPD) patterns. We demonstrate the power of XPD as a fingerprinting tool and conclude that Pb occupies Bi sites and Dy the Ca sites. The presence of the incommensurate lattice modulation is not visible in XPD, probably due to a Pb-induced, reduced modulation amplitude.