Characterization of a Non-Superconducting Cuprate, Bi2Sr2YCu2O8.5

A new Bi-containing cuprate, Bi2Sr2YCu2O8.5, was found in the course of substitution study for high T c compounds Bi2Sr2CaCu2O8+y . Bi2Sr2YCu2O8.5 is a semiconductor and undergoes an antiferromagnetic transition at about 13 K which is considered to originate from the ordering of Cu in the CuO2 planes. An electron diffraction study revealed the existence of a superstructure. The unit cell taking account of the superstructure is 1×8×1 of the original unit cell (5.47×5.43×30.18 Å3). Analogy of three kinds of oxide systems, (La1-x Sr x )2CuO4, YBa2Cu3O6+x , and Bi2Sr2Ca x Y1-x Cu2O8+y , is discussed.