Suppression of superconductivity with Pr substitution in Nd1-xPrxBaCaCu3O7system

The structural, superconducting and magnetic properties of Nd1-xPrxBaCaCu3O 7 system with x = 0.0, 0.10, 0.25, 0.35, 0.50, 0.75 and 1.0 have been inves tigated. X-ray diffraction results reveal that Pr substitutes isostructural ly in NdBaCaCu3O7 (Nd:1113) superconductor with complete solubility. The su perconducting transition temperature (T-c), measured by ac susceptibility t echnique, decreases with increasing x. However, suppression of T-c with inc reasing Pr substitution is less in Nd:1113 superconductor compared to that reported for Nd1-xPrxBa2Cu3O7 system. Interestingly, in the fully Pr substi tuted compounds of the above series, i.e., in PrBaCaCu3O7 and PrBaxCu3O7, t he Pr moments order antiferromagnetically with T-N of 10 and 17 K, respecti vely. The present results along those reported earlier [V.P.S. Awana, J. Ho rvat, S.X. Dou, A. Sedky, A.V. Narlikar, J. Magn. Magn. Mater., 182 (1998) L280; V.P.S. Awana, S.X. Dou, S.K. Malik, Rajvir Singh, A.V. Narlikar, D.A. Landinez Tellez, J.M. Ferreira, J. Albino Aguiar, S. Uma, E. Gmelin, W.B. Yelon, J. Magn. Magn. Mater., 187 (1998) 192], clearly suggest that there i s a correlation between the T-c suppression due to Pr and the magnetic orde ring temperature of the fully substituted Pr moments in these systems. The T-N may be taken to be a measure of the strength of hybridization between t he Pr-4f electrons with Cu-O conduction band, and hence a lower T-N may imp ly a less deleterious effect on superconductivity. (C) 1999 Elsevier Scienc e B.V. All rights reserved.