The conductivity and ionic transport of doped bismuth titanate pyrochlore Bi1.6МxTi2O7 − δ (М – Mg, Sc, Cu)
Abstract Pyrochlores Mg-, Sc-, Cu-doped bismuth titanates have been obtained. The results of X-ray powder diffraction structure refinement and the pycnometric density measurement point to the preference of the dopants distribution in the A-sites of the pyrochlore structure. Electric properties were studied for single phase compounds. The mixed electron-ionic conductivity was indicated in these samples. The high temperature ( T  > 300 °C) relaxation process was observed in Bi 1.6 M x Ti 2 O 7 − δ at the range of frequency 10 3 –10 6  Hz. Oxygen mobility and surface reactivity of Bi 1.6 M 0.2 Ti 2 O 7 − δ (M – Sc, Mg and Cu) and Bi 1.4 Mg 0.2 Ti 2 O 7 − δ samples were studied by using temperature programmed isotope exchange (TPIE) with C 18 O 2 in flow and closed reactors. According to TPIE data the regular lattice oxygen is homogeneous from the point of view of its mobility.