Kevin S. Knight

Perovskite solid electrolytes: Structure, transport properties and fuel cell applications

Abstract Doped barium cerate perovskites, first investigated by Iwahara and co-workers, have ionic conductivities of the order of 20 mS/cm at 800 °C making them attractive as fuel cell electrolytes for this temperature region. They have been used to construct laboratory scale fuel cells, which, in addition to performance data, have provided an unexpected insight into the transport processes operating in these materials. In the temperature range of 600–1000 °C, the dominant transport process varies from protonic to oxide-ion dominated. This transition has been confirmed by measurement of water vapour transfer in a cell in which the perovskite is exposed to wet hydrogen on both sides. The evolution of transport properties with temperature is discussed in relation to structure. Neutron diffraction studies of doped and undoped barium cerate are reported, revealing a series of phase transitions between ambient temperature and 1000 °C. The available literature on chemical stability of cerate perovskites to reduction and attack by carbon dioxide is reviewed in brief.

Ferroelectric-paraelectric transition in BiFeO3: crystal structure of the orthorhombic beta phase.

A detailed investigation using variable temperature powder neutron diffraction demonstrates that

Ionic conductivity of gadolinium-doped barium cerate perovskites

{\mathrm{BiFeO}}_{3}

Ferroelectric-Paraelectric Transition inBiFeO3: Crystal Structure of the OrthorhombicβPhase

undergoes a phase transition from the ferroelectric

Thermal expansion and crystal structure of cementite, Fe3C, between 4 and 600 K determined by time-of-flight neutron powder diffraction

\ensuremath{\alpha}

Structural phase transitions in BaCeO3

phase (rhombohedral,

Negative linear compressibility and massive anisotropic thermal expansion in methanol monohydrate

R3c

Structural phase transitions, oxygen vacancy ordering and protonation in doped BaCeO3: results from time-of-flight neutron powder diffraction investigations

) to a paraelectric

The Polar Phase of NaNbO3: A Combined Study by Powder Diffraction, Solid-State NMR, and First-Principles Calculations

\ensuremath{\beta}

The crystal structures of some doped and undoped alkaline earth cerate perovskites

phase (orthorhombic,