Moessbauer spectroscopic study of iodine-intercalated Bi2Sr2CaCu2Oy

Iodine-intercalated high-Tc oxide Bi2Sr2CaCu2Oy was studied at 16 K using 129I Moessbauer effect. The Moessbauer spectrum shows the presence of I-3 ions which have an almost linear structure and a symmetrical charge population, and no other iodine species are found. In addition to the electronic structure of each iodine species, the analysis of the intensity ratios of the quadrupole-split transitions reveals information about the anisotropy of the recoilless fraction for each iodine atom. It cannot exclude the possibility that the I-3 ion is slightly asymmetrical and/or bent with consideration to small interactions between the I-3 ion and the neighboring Bi-O layers. (orig.)