Mixed ionic–polaron transport and rapid crystallization in (Bi,Pb)–Sr–Ca–Cu–O glass

The results of a.c. electrical conductivity measurements in (Bi,Pb)–Sr–Ca–Cu–O glasses were reported. Two components of total conductivity were observed. Activation energies of both processes were determined. The small polaron hopping between copper ions in a different valency state CuI –CuII is one process. We propose that the second is ionic conductivity caused by CuI ions.