Magnetic ordering and superconductivity in Y1-xPrxBa2Cu3O7-y

An extensive study of magnetic, thermal, transport, and structural properties of the alloy Y1-xPrxBa2Cu3O7-y is presented. The endpoints of the alloy series are a high-temperature superconductor Y-Ba-Cu-O and an antiferromagnetic semiconductor (Pr-Ba-Cu-O, TN=17 K). The superconducting transition temperature is reduced with increasing Pr concentration following the Abrikosov-Gorkov pair-breaking curve with critical concentration xcr=0.62. Alloying also reduces the Néel temperature approximately linearly with the Y content, and there is a concentration region (0.4<x<0.6) where antiferromagnetism and superconductivity is suggested to coexist. The specific heat, the susceptibility, the magnetic ordering, and the metal-to-semiconductor transition seen in the resistivity are consistent with the picture that Y3+ is replaced by Pr4+ with some degree of valence admixture of the Pr3+ configuration. © 1989 The American Physical Society.