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 gamma-Bi4V2O11 structure was obtained for a treatment at temperatures over 550 degrees C whereas BITAVOX.20 started to crystallise at 425 degrees 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. (C) 2014 Elsevier B.V. All rights reserved.