Anionic conduction properties of BiCaPb mixed oxides

• Published in: Solid state ionics 1992-10, Vol.57 (3), p.245-249
• Main Authors: Drache, M., Conflant, P., Boivin, J.C.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Diffusion in solids; Exact sciences and technology; Physics; Self-diffusion and ionic conduction in nonmetals; Transport properties of condensed matter (nonelectronic)
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/0167-2738(92)90154-H

This study of the Bi 2O 3CaOPbO system has determined the equilibrium domains of existence of three solid solutions which belong respectively to the fcc (δ-Bi 2O 3), rhombohedral (BiSrO) and bcc (anti-α-AgI) structural types. The first two solid solutions can be preserved at room temperature in a metastable or/and a stable form within a significant range of composition. They have been investigated by impedance spectroscopy and transport number measurements. In all cases, the substitution of Bi 3+ by the divalent cations leads to a decrease of the conductivity. However, for a constant M 2+ concentration, the conductivity increases slightly with the Pb 2+/Ca 2+ ratio without significant modification of the activation energy. Transport number measurements, performed particularly on the δ-phase, have shown, at low temperature (≤400 °C), a very attractive quick response to any P O2 variation. The corresponding Nernst potentials were shown to be significantly higher than expected from the classical O 2/O 2- electrode equilibrium.