High-Tc Superconductivity in New Oxide Systems and Their X-Ray Diffraction Study

Resistivity measurements for Ln-Ba-Cu-O systems with Ln being lanthanide atoms have been carried out. In addition to the previously reported systems with Ln=Lu, Yb, Tm, Er, Ho, Dy and Eu, we have discovered the high- T c superconductivity in the systems with Ln=Nd, Sm and Gd. Preliminary results of X-ray powder diffraction study are given and the superconductivity is discussed in relation to them.