Bi4V2O11 and BITAVOX.20 coatings deposited by reactive magnetron sputtering

• Bi4V2O11 and BITAVOX.20 were synthesized by reactive magnetron co-sputtering.
• Crystallization of the coatings was studied by X-ray diffraction in temperature.
• High temperature γ form grows from a new type of intermediate phase.
• The conductivity of Bi4V2O11 coatings was investigated by impedance spectroscopy measurements along the sample surface.

Bi4V2O11 and BITAVOX.20 films were deposited by magnetron sputtering in reactive conditions from Bi, V and Ta metallic targets. The influence of sputtering conditions on the films composition was studied and then a structural study at variable temperature was carried out. Before annealing, the films were amorphous and the γ-Bi4V2O11 structure was obtained for a treatment at temperatures over 550 °C whereas BITAVOX.20 started to crystallise at 425 °C. In both cases, crystallisation occurred via an intermediate fluorite phase presenting a tetragonal deformation as already observed for other compounds with the Aurivillius structure.