Aerosol deposition of (Cu,Ti) substituted bismuth vanadate films

• Cu and Ti doped bismuth vanadate films were prepared by aerosol deposition (AD).
• Dense 3–5 μm thick films were deposited on alumina, silicon and gold electrodes.
• Annealing of the AD-layer increases the conductivity by 1.5 orders of magnitude.
• Effect of temperature on structure and microstructure was investigated.

Bismuth vanadate, Bi4V2O11, and related compounds with various metal (Me) substitutions, Bi4(MexV1−x)2O11−δ, show some of the highest ionic conductivities among the known solid oxide electrolytes. Films of Cu and Ti substituted bismuth vanadate were prepared by an aerosol deposition method, a spray coating process also described as room temperature impact consolidation. Resultant films, several microns in thickness, were dense with good adhesion to the substrate. Scanning electron microscopy and high temperature X-ray diffraction were used to monitor the effects of temperature on the structure and microstructure of the film. The particle size remained nano-scale while microstrain decreased rapidly up to 500 °C, above which coarsening and texturing increased rapidly. Impedance measurements of films deposited on inter-digital electrodes revealed an annealing effect on the ionic conductivity, with the conductivity exceeding that of a screen printed film, and approaching that of bulk ceramic.