Composition dependence of polymorphism and electrical conductivity in Ce(IV)-doped Bi4V2O11

For the first time, a new member of the BIMEVOX family, namely BICEVOX, has been synthesized by the partial solid-state substitution of Ce(IV) for vanadium in parent Bi₄V₂O₁₁ solid electrolyte. The electrical conductivity in Bi₄Ce _x V_{2? x} O_{11?( x /2)? δ} has been investigated in the compositional range 0 ≤ x ≤ 0.30, using FT-IR, X-ray powder diffraction, differential thermal analysis and ac impedance spectroscopy. Owing to the long-term stabilization of α- and β-polymorphs compared to other members of the BIMEVOX family, the BICEVOX system may be a prospective solid electrolyte for intermediate temperature solid oxide fuel cells due to the significantly increased conductivity at lower temperatures observed for the compositions x > 0.20.