α-MoO3 thin ？lms prepared by spray pyrolysis

MoO3 thin ？lms have been deposited on clean glass slides using the spray pyrolysis technique. The samples were grown with di？erent thicknesses by spraying on common glass substrates a solution of(ammoniummolybdatetetrahydrate) ((NH3)6Mo7O244H2O). The samples were characterized by X-ray di？raction (XRD), infrared spectroscopy, scanning electron microscopy (SEM) and electrically through electrical resistivity measurements as a function of temperature. It was found that samples present crystalline structure associated with the alpha phase of MoO3 grown with preferential direction of growth along the planes (0k0). As result of increasing the volume of precursor solution sample surface becomes porous. The change in electrical resistance of MoO3 ？lms by exposure to carbon monoxide (CO) at room temperature, makes the ？lms obtained by this technique could be promising in its use in gas sensing devices at room temperature