IODINE INTERCALATION IN BI2SR2CA(CU1-ZCOZ)(2)O8-VALUES(DELTA WITH DIFFERENT DELTA)

The effects of iodine intercalation have been investigated for the Co- substituted Bi-2212 phase Bi2Sr2Ca(Cu1-zCoz)(2)O-8+delta with differen t delta values in the overdoped regime. Whereas in the pristine sample s T-c depends on z and delta, in the intercalated ones T-c is independ ent of delta. This indicates that the hole concentration in the Bi-221 2 phase has an upper limit and becomes saturated by the transfer of ho les from the intercalated iodine. T-c(z)/T-c(z = 0) of the intercalate d samples differs Tram that of the pristine ones. This suggests that t he intercalation of iodine decreases T-c not only through an increase in p, but also through a structural change, probably the interlayer de coupling between adjacent blocks of the CuO2 planes.