Effect of Co-Doping on the Electrical Properties of Magnesium and Copper-Containing Bismuth Niobate with Pyrochlor-Type Structure

Ruthenium-codoped bismuth niobate Bi1.5Cu0.375Mg0.375Nb1.45Ru0.05O7-δ with the pyrochlore structure was obtained by Pechini method. The distribution of Ru4+ over Nb5+ sites was established by structural analysis. According to the data of optical reflectance spectra, the optical band gap decreases from 2.40 to 2.27 eV for the sample doped with ruthenium. A small amount of ruthenium in the system was found to result in an increase in conductivity by 0.5 orders of magnitude compared to Cu-Mg-substituted bismuth niobate, due to an increase in the electronic component of the conductivity.