Atmospheric pressure chemical vapour deposition and characterisation of crystalline InTaO4, InNbO4 and InVO4 coatings

The possibilities to grow crystalline complex InTaO4, InNbO4 and InVO4 coatings as well as single oxide layers In2O3, Ta2O5, Nb2O5, and VOx were investigated using aerosol assisted atmospheric pressure chemical vapour deposition technique. Indium(III) and niobium(IV) tetramethylheptanedionates, tantalum(V) tetraethoxyacethylacetonate and vanadium(III) acethylacetonate were used as precursors, monoglyme and toluene as solvents. The influence of deposition conditions and solution composition on elemental and phase compositions of layers was studied. Indium tantalate layers containing pure monoclinic InTaO4 phase were obtained ex-situ, i.e., after high-temperature (800 °C) annealing of layers grown at lower temperature (500 °C). Films containing pure orthorhombic indium vanadate or monoclinic indium niobate phase may be prepared using both in-situ (600 °C) or ex-situ (deposition at 400 °C, annealing at 800 °C) approaches. Under optimised deposition conditions and solution compositions, Ni-doped InVO4 and InTaO4 films were also deposited and their photocatalytic activity was tested.