Superionic and superconducting nanohybrids with heterostructure, AgxIwBi2Sr2Can-1CunOy (0.76≤x≤1.17, n = 1, 2, and 3)

New mixed conducting hybrid systems, AgxIwBi2ST2Can-1CunOy (n = 1, 2, and 3), have been developed successfully by intercalating the superionic conducting A-I layer into the superconducting Bi2Sr2Can-1CunOy lattice. Although the Ag-I intercalation gives rise to a remarkable basal increment of similar to 7.3 A, which is twice as large as that of the iodine intercalate (Delta d = 3.6 Angstrom), it has little influence on the superconducting property with only a slight T-c depression. Systematic X-ray absorption near edge structure (XANES)/extended X-ray absorption fine structure (EXAFS) studies clearly reveal the charge transfer between host and guest, indicating that a change in hole concentration of the CuO2 layer is the main origin of T-c evolution upon intercalation. According to the ac impedance and de relaxation analyses, the AgxIwBi2Sr2Can-1CunOy compounds possess fast ionic conductivities (sigma(i) = 10(-1.4)-10(-2.6) Omega(-1) cm(-1) at 270 degrees C) with the activation energies of 0.22 +/- 0.02 eV, which are similar to those of other two-dimensional Ag+ superionic conductors. A more interesting finding is that these intercalates exhibit both high electronic and ionic conductivities with ionic transference numbers of t(i) = 0.02-0.60, due to their interstratified heterostructures consisting of a superionic conducting silver iodide layer and a metallic host layer. A close relationship between local crystal structure and ionic conductivity has been elucidated from the detailed Ag K-edge EXAFS analyses, where a reasonable pathway for Ag+ ionic conduction is suggested along with the intracrystalline structure of the Ag-I sublattice.