Abstract
During the investigation of the Bi-Sr-La-Cu-O system, a family of bismuth oxides with the composition of Bi_2Sr_<2-x>La_zCuO_y (x=0.3-0.6, z=0.2-0.3) has been found to exhibit a superconducting transition with an onset temperature near 27 K and zero resistivity at 5 K. The major phase is an incommensurate one with a composition of Bi_2Sr_La_<0.2>CuO_y and is orthorombic with unit cell dimensions of a=0.538, b=0.542×n and c=2.43 nm where n is a nonintegral number of 4.3.