Abstract
SmBa2Cu3Oy and GdBa2 Cu3Oy with various y have been prepared by quenching and by the reduction in N2 gas, and their superconducting properties were examined by electrical resistivity and χao measurements. The superconducting transition temperature Tc1' determined by χao seems to decrease stepwise with decreasing y. This suggests the existence of 60 K-class superconductor, similar to YBa2Cu3Oy.
