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Abstract
An extensive study of magnetic, thermal, transport, and structural properties of the alloy ${\mathrm{Y}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Pr}}_{\mathit{x}}$${\mathrm{Ba}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathit{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, ${T}_{N}$=17 K). The superconducting transition temperature is reduced with increasing Pr concentration following the Abrikosov-Gorkov pair-breaking curve with critical concentration ${x}_{\mathrm{cr}=0.62}$. Alloying also reduces the N\'eel 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 ${\mathrm{Y}}^{3+}$ is replaced by ${\mathrm{Pr}}^{4+}$ with some degree of valence admixture of the ${\mathrm{Pr}}^{3+}$ configuration.
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