X-ray photoelectron spectroscopy (XPS) shows that iodine intercalated into the (Bi-O) layers of the oxide superconductor Bi2Sr2CaCu2Ox is present in a highly oxidized I(VII) state suggestive of the formation of strongly covalent I-O bonds as in KIO4, not as in KIO3. Electrons are transferred from the antibonding states of the covalent complex to the CuO2 sheets, which lowers Tc. The core-level spectra also show the presence of residual iodine species at the surface of the samples. Ar-ion sputtering of the surface disintercalates iodine from the bulk to the surface.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry