Superconducting onsets near 90 K are observed in multiphase samples with nominal composition ${\mathrm{Lu}}_{1.8}$${\mathrm{Ba}}_{0.2}$${\mathrm{CuO}}_4$. Results of electrical resistance, mutual inductance, and dc magnetization measurements are reported. Magnitude of superconducting transitions indicates that about 2% of the best sample is superconducting.

• Received 2 March 1987

DOI:https://doi.org/10.1103/PhysRevLett.58.1885