Abstract
We report the results on structural aspects, magnetic, and superconducting properties of the La1-xPrxBaCaCu3O7 system. Both x-ray and neutron diffraction studies reveal that Pr substitutes isostructurally in the tetragonal LaBaCaCu3O7 (La:1113) system until the complete replacement of La by Pr. The superconducting transition temperature, Tc , determined from ac susceptibility measurements decreases, with increasing x. The relative Tc depression due to Pr in the LaBaCaCu3O7 superconductor is less in comparison to that found for La-site Pr substituted LaBa2Cu3O7 (La:123). While the critical Pr concentration (xcr) to completely suppress the superconductivity in the former is around 70 at. % of Pr at La site, the same is reported as only 30 at. % for the latter. For nonsuperconducting samples, i.e., for x=0.70 and 1.0, possible antiferromagnetic ordering with Neel temperatures, TN , of 4 and 8 K, respectively, are observed from both dc magnetic and heat capacity measurements. Interestingly in the La1-xPrx :1113 system the xcr of Pr is 0.70, and TN of Pr:1113 is 8 K, while for the La1-xPrx :123 system xCr is 0.30 and TN of Pr:123 is 17 K. The results are explained on the basis of distribution of Pr at both RE and Ba sites in the RE:1113 structure. This leads to a lower TN and a less deleterious effect of Pr on superconductivity of La:1113 compared to La:123.
Publication Details
This article was originally published as Awana, VPS, Dou, SX, Singh, R, Narlikar, AV, Malik, SK and Yelon, WB, Magnetic and superconducting properties of Pr in La12xPrxBaCaCu3O7 system with 0.0