Iodine and lithium intercalation into the high-T sub(c) superconducting oxide Bi sub(2)Sr sub(2)CaCu sub(2)O sub(y)

The kinetics of formation of the iodine intercalate of Bi sub(2)Sr sub(2)CaCu sub(2)O sub(y) have been studied. Upto one iodine atom per 2212 formula unit was incorporated into the structure; under the conditions of reaction used no second-stage compound was observed. The activation energy for the diffusion of iodine molecules in the interlayer of the intercalation compound was determined (45 kJ/ mol). Lithium diffusion into the structure was studied chemically and electrochemically and was found to saturate at about x = 0.3 in Li sub(x)Bi sub(2)Sr sub(2)CaCu sub(2)O sub(y); the lithium has a diffusion coefficient around 10 super(-13) cm super(2)/s. A small expansion of the lattice was observed. The superconductive properties were not improved by iodine or lithium intercalation.