Magnetic ordering and superconductivity in Y sub 1 minus x Pr sub x Ba sub 2 Cu sub 3 O sub 7 minus y

An extensive study of magnetic, thermal, transport, and structural properties of the alloy Y{sub 1{minus}{ital x}}Pr{sub {ital x}}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{ital 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, {ital T}{sub {ital N}}=17 K). The superconducting transition temperature is reduced with increasing Pr concentration following the Abrikosov-Gorkov pair-breaking curve with critical concentration {ital x}{sub cr}=0.62. Alloying also reduces the Neel temperature approximately linearly with the Y content, and there is a concentration region (0.4{lt}{ital x}{lt}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 Y{sup 3+} is replaced by Pr{sup 4+} with some degree of valence admixture of the Pr{sup 3+} configuration.