Unveiling the mesoscopic disorder induced by Al-doping in SmBa2Cu3-xAlxO6+ superconductors by mean of the reciprocal and real space analysis of Synchrotron Radiation XRPD data

Inhomogeneity at the nanoscale and strong disorder seem to be crucial in determining the physical properties of strongly correlated systems, like superconductors1. A precise knowledge of the short and medium range structure of these materials is then needed and it can be obtained through the combined real space and reciprocal space analysis of diffraction patterns. In this work the disorder induced by Al doping in SmBa2Cu3O6+ superconductors is determined by means of the reciprocal and real space analysis of Synchrotron Radiation XRPD data collected on both Al-free and Al-doped samples. The effect of Al doping on the mean structure (i.e. on space group, mean atomic positions and atomic mean square displacements) were determined using the Rietveld analysis while Pair Distribution Function (PDF) Technique allowed to map quantitatively the structural distortions in the neighborhood of Al dopant as well as the spatial extension of disorder. In particular Al doping causes the corrugation in the superconducting Cu2-O2/3 planes, strongly affecting the superconducting properties of this material