XANES AND EXAFS STUDIES ON A NEW SUPERCONDUCTING INTERCALATION COMPOUND, AGIBI2SR2CACU2OY

A new superconducting intercalation compound, AgIBi2Sr2CaCu2Oy, in whi ch the basal spacing is increased by 7.352 Angstrom, has been prepared from the mixture of polycrystalline Bi2Sr2CaCu2Oy and Ag powder under iodine vapor at 190 degrees C in an ambient atmosphere. The X-ray abs orption studies on I L(I)- and Ag K-edges indicate that there is no ch arge-transfer between the intercalated guest species, AgI and host lay er. A slight T-C depression (Delta T-C approximate to 13K) upon AgI in tercalation is, therefore, probably due to the weakening of interlayer coupling, but the hole donation to the host upon oxygen intercalation may not be excluded.