The conditions for the solid-state reaction between iodine and Bi2Sr2C
an-1CunOx (n = 2, 3) have been studied, Only oxygen-deficient host lat
tices reacted with halogen to yield stage- one intercalation compounds
, whereas oxygen-enriched hosts underwent decomposition. The differenc
e in reactivity has been correlated to relative changes in the oxygen
concentrations of the host lattices by ac-susceptibility measurements
and X-ray powder diffraction. The charge transfer caused by intercalat
ion is estimated to be 0.04 < Delta N-c < 0.1.