Impact of the starting powder composition on GdSr2RuCu2O8 Melt-Textured Processes

In order to achieve MTG samples with higher oriented volume fractions, we prepared pellets adding either GdSr(2)RuO(6) (Gd1210) or CuO to highly pure Gd1212 powders. X-ray Diffraction (XRD) analysis revealed a substantial difference between the two systems showing that only in Gd1212-Gd1210 samples it is possible to achieve a superconducting phase. The analysis of the two samples microstructures carried out by Scanning Electron Microscopy with implemented Energy Dispersive Spectroscopy (EDS) revealed that in the case of the Gd1212-Gd1210 samples a low concentration of Gd1210 and SrRuO(3) inclusions is observed in a Gd1212 predominant matrix. However, in the Gd1212-CuO samples, micro-sized precipitates of SrRuO(3), islands of Gd(2)CuO(4) are homogeneously distributed throughout a CuO matrix. DTA measurements performed on all the samples confirm the presence of additional solidification reactions in the Gd1212-CuO samples. These features have a profound impact on the transport properties of the two samples. The addition of Gd1210 in highly pure Gd1212 powders has been proved to be a favorable condition to obtain superconducting Gd1212 MTG samples.