A New High-T_c Oxide Superconductor without a Rare Earth Element

Abstract

We have discovered a new high- T c oxide superconductor of the Bi-Sr-Ca-Cu-O system without any rare earth element. The oxide BiSrCaCu 2 O x has T c of about 105 K, higher than that of YBa 2 Cu 3 O 7 by more than 10 K. In this oxide, the coexistence of Sr and Ca is necessary to obtain high T c .