Impedance spectra of BICUVOX (Bi2Cu0.1V0.9O5.35) with platinum or gold
electrodes, measured over broad frequency and temPerature range, were
simulated by the impedance of an equivalent circuit composed of resis
tors, capacitors and constant phase elements. The assignment of the ci
rcuit elements to the bulk of electrolyte and to the electrode process
was proved by their scaling with the geometric factor and by comparis
on with the ac four-probe measurement. Separation of contributions of
grain interiors and grain boundaries to the resistance of BICUVOX was
possible below 670 K, The Arrhenius plot of the total conductivity con
sisted of two straight sections, with a change of slope at about 740 K
. The charge transfer reaction at the electrode was evident above 770
K.