A MISSING LINK IS FOUND - A NOVEL HOMOLOGOUS SERIES OF SUPERCONDUCTING PB-BASED CUPRATES

A new Pb-based superconductor containing the Pb-1223 phase has been su ccessfully synthesized by means of a high-pressure technique. Bulk sup erconductivity has been detected at temperatures below 115 K. This mea ns that a new superconducting homologous series, Pb-12(n-1)n, exists. To date, there exist homologous series of superconducting layered cupr ates for each of the M-(Ba, Sr)-Ca-Cu-O systems where M stands for an element with the atomic number between 80(Hg) and 83(Bi) except 82(Pb) -a missing link. This missing link has been found.