1988 年 14 巻 3-4 号 p. 199-203
A new compound Er_2Ba_2Cu<1+χ>Pt<1-χ>O_8 (χ≒0.1) was discovered as single crystals. X-ray crystal structure analysis revealed that the crystal structure is orthorhombic (space group: Pcmn) with cell dimensions of a= 10.287 (3) Å, b=5.659 (1) Å and c=13.157 (3) Å, The crystal contains double zig-zag chains composed of Cu, O and Pt ions running parallel to the b axis. A Iarge diamagnetic transition was observed below 80-90 K in the aggregates of the single crystals. However we can not draw, at present, a definitive conclusion as to whether the new compound is really the superconductor or not. Further investigation on the magnetic and electrical properties are now in progress.