INTERCALATION OF BR AND LI IN BI2SR2CAN-1CUNO2N+4

Effects of intercalation of Br and Li into Bi2Sr2Can-1CunO2n+4 (n = 1, 2, 3) have been investigated. For Br-intercalated samples of n = 2 and 3, intercalation compounds Bi2Sr2Can-1CunO2n+4Br with enlarged unit cells along the c-axis are synthesized. For Li-intercalated samples, it is not clear whether Li atoms act as intercalants or oxygen getters. For lightly Br- and Li-intercalated samples, the electrical resistivity, the Hall coefficient and T(c) change depending on the quantity of intercalants, which is attributable to charge transfer between intercalants and CuO2 planes. For n = 3, T(c) decreases by the intercalation of both Br and Li, suggesting that Bi2Sr2Ca2Cu3O10 has almost optimum hole concentration to attain the maximum of T(c). In conclusion, the intercalation is effective for controlling the carrier concentration in CuO2 planes.