MoO2(acac)(2) has been used as a precursor for the one-step MOCVD of silica- and zirconia-supported MoO3. Pure films were obtained by suitable control of the deposition parameters. The films were characterised by W-VIS spectroscopy, XRD, SEM, wavelength-dispersive X-ray fluorescence analysis and XPS. Silica-supported MoO3 consists of a layered structure packed in the direction of the b axis whilst no preferential orientation was observed for the zirconia-supported films. Films deposited using higher O-2/MoO2(acac)(2) molar ratios consist of pure MoO3, whilst lower O-2/MoO2(acac)(2) values result in the copresence of some Mo suboxides. Deposition rates appear to be largely governed by the O-2/MoO2(acac)(2) molar ratio and they always increase upon decreasing this parameter. Larger crystallite sizes were found to be associated with slower rate regimes.
Synthesis and spectroscopic characterisation of MoO3 thin films
GULINO, Antonino;CONDORELLI, Guglielmo Guido;
1996-01-01
Abstract
MoO2(acac)(2) has been used as a precursor for the one-step MOCVD of silica- and zirconia-supported MoO3. Pure films were obtained by suitable control of the deposition parameters. The films were characterised by W-VIS spectroscopy, XRD, SEM, wavelength-dispersive X-ray fluorescence analysis and XPS. Silica-supported MoO3 consists of a layered structure packed in the direction of the b axis whilst no preferential orientation was observed for the zirconia-supported films. Films deposited using higher O-2/MoO2(acac)(2) molar ratios consist of pure MoO3, whilst lower O-2/MoO2(acac)(2) values result in the copresence of some Mo suboxides. Deposition rates appear to be largely governed by the O-2/MoO2(acac)(2) molar ratio and they always increase upon decreasing this parameter. Larger crystallite sizes were found to be associated with slower rate regimes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
