Anomalous X-ray diffuse scattering study of local order in Nd 2−xCe xCuO 4−y

Abstract

We have successfully applied the anomalous X-ray diffuse scattering technique to study the short-range order and the lattice distortions in the electron-type ceramic superconductor Nd 2−xCe xCuO 4−y. The intensity measurements were made at two energies below the absorption edge of Ce. The data set were analyzed using a kinematic diffraction equation expanded up to the second order in atomic displacements. The fitted SRO parameters for the composition of Nd 1.85Ce 0.15CuO 4−y suggest the formation of Ce atom-pairs along the <001> direction. The clustering of the Ce atoms reduces the disturbance to the parent structure.