Mossbauer spectroscopy and radiofrequency absorption investigations of Pr substituted 1-2-3 type compounds

Fe-57 and Eu-151 Mossbauer spectroscopy as well as RF susceptibility measur ements were applied to study the effects of Pr substitution either into the rare earth or into the Ba site in Eu1-xPrxBa2Cu3O7-delta and EuBa2-xPrxCu3 O7-delta, respectively. Site mixing of Pr between the rare earth and Ba sit es could be excluded by the utilization of Fe-57 Mossbauer spectroscopy. It was found that there exists a correlation between the Eu-151 isomer shift and the onset temperature of the superconducting transition independent of the location of Pr. RF susceptibility measurements provide an evidence for a difference in the magnetic moment of Pr substituted for the Eu or Ba site s. The obtained results can be explained by hole filling as the dominant ef fect of Pr substitution.