It was recalled that bismuth oxide in its δ-phase (high-temperature fluorite structure) was a well-known solid electrolyte owing to its high O ion conductivity. Here, δ-Bi2O3 thin film was stabilized at room temperature by electrodeposition on different conductor substrates. Electrodeposited thin films have a good quality with an excellent adhesion to the substrate. The crystalline structure and the stability of the deposit were studied by X-ray diffraction. Both X-ray diffraction measurements and transmission electron microscopy investigation revealed the nanocrystallinity of the films. X-ray diffraction measurements showed a decrease of nanocrystallites size after thin film annealing. The resistivity measurements showed an excellent conductivity of electrodeposited δ-Bi2O3 thin films with an ionic conductive behaviour and an electrical conductivity value close to the theoretical value: the thin film deposited on a gilded silver substrate exhibited a conductivity of 0.39S/cm at 440C.

Structure and Conductivity Studies of Electrodeposited δ-Bi2O3. K.Laurent, G.Y.Wang, S.Tusseau-Nenez, Y.Leprince-Wang: Solid State Ionics, 2008, 178[33-34], 1735-9