Anomalous suppression of superconductivity in Zn-substituted

We have found an anomalous suppression of superconductivity at (Formula presented), where (Formula presented) (the hole concentration per Cu) (Formula presented), in the partially Zn-substituted compound (Formula presented) with (Formula presented). In these samples with (Formula presented) and (Formula presented), transport properties such as electrical resistivity and thermoelectric power exhibit less metallic behavior than usual. There is a possibility that a kind of order of holes and/or spins is stabilized owing to pinning by Zn, as in the La-based cuprate. It is likely that the so-called “1/8 problem” is not only characteristic of the La-based cuprate but also common to all high-(Formula presented) cuprates including (Formula presented) planes in their crystal structures.