Nd:YAG pulsed laser deposition of AlVO4 thin films on alumina and monocrystalline MgO

AlVO4 thin films were prepared by infrared Nd:YAG pulsed laser deposition on two different substrates (polycrystalline Al2O3 and monocrystalline MgO). The distance between the target-substrate (30 mm) and the partial oxygen pressure (0.14 mbar) during the deposition process were chosen taking into account the previous experiences with other oxides. The substrate temperature was varied between 300 and 600 -C finding an optimum at about 400 -C. At higher temperatures, the vanadium seems to evaporate from substrate surface with a strong change of stoichiometry. Preferential growth of AlVO4 films in the direction (022), were grown on MgO substrates. A very high sensitivity of these films to a flux of NO2 gas is also shown.