CRYSTAL-STRUCTURE AND ANISOTROPY OF IODINE-INTERCALATED BI2SR2CAN-1CUNOX

The electronic state and structural configuration of the intercalated iodine species in stage-1, I-Bi2Sr2Can-1CunOx (n = 1, 2), have been st udied through polarization-resolved Raman and I-129 Mossbauer spectros copy. The polarization dependence of the Raman spectra and the Mossbau er measurement confirmed the dominant species to be triiodide ions, I3 -, with alignment of these linear molecules either along the a- or b-a xis in the host crystals. Transport measurements such as thermoelectri c power and Hall coefficient clearly indicated that hole carriers are doped into the CuO2 planes upon intercalation, by which T(c) of the ho st superconductor is changed. Furthermore, based on resistivity measur ements in a magnetic field, we suggest that the iodine intercalation l eads to a decrease of the anisotropy both in normal and superconductin g states, suppressing the extremely two-dimensional character of the B i2Sr2Can-1CunOx systems.