Low-temperature heat-capacity, electrical resistivity, and magnetization measurements are performed to investigate the superconducting and magnetic behavior of $\mathrm{Er}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-x}$. This compound exhibits a superconducting transition at 84 K as determined from zero resistance and Meissner effect. A well-defined magnetic transition is seen at 0.87 K from heat-capacity measurements. We deduce the coexistence of superconductivity and antiferromagnetic order in this compound; however, magnetization data show that the paramagnetism from ${\mathrm{Er}}^{3+}$ and superconductivity are independent, leading to indirect evidence of extremely anisotropic superconductivity in this class of compounds.

• Received 11 August 1987

DOI:https://doi.org/10.1103/PhysRevB.36.8791