Magnetic and superconducting properties ofRBa2Cu3Oxcompounds

Abstract

Specific-heat and dc magnetic-susceptibility measurements have been performed on $R{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_x$ ($R$ denotes rare earth) compounds. These measurements show that the rare-earth atoms behave as local moments above the superconducting transition temperature of these compounds which can be as high or higher than in nonmagnetic $\mathrm{Y}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_x$. Further, we find coexistence of superconductivity and magnetism in $R=\mathrm{G}\mathrm{d},\mathrm{E}\mathrm{r},\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{D}\mathrm{y}$ compounds and evidence for crystalline-electric-field splittings in these materials.