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Molybdenum oxide thin films find diverse applications as catalysts, gas sensors, and electrochromic devices. Such films are produced mainly by reactive sputtering and thermal evaporation but other techniques such as chemical vapor deposition and electrochemical deposition have been used. In the present work, the feasibility of an alternative method for the production of molybdenum oxide films using a molybdenum filament heated in a rarefied oxygen atmosphere is demonstrated. The filament heating current, I F , and the oxygen flow rate, F O 2 , are the key deposition parameters and their effect on the deposition rate, R, was investigated. For I F ) 12.5 A, an increase in the R-value from 7.5 to 31 nm/min was observed as F O 2 was increased from 6.0 to 21 sccm. To characterize the chemical bonds, infrared spectroscopy, using both unpolarized and p-polarized infrared beams, and X-ray photoelectron spectroscopy (XPS) were employed. Line shape analysis of the Mo(3d) XPS peak revealed that the Mo atoms were in mixed valence states, Mo 6+ and Mo 5+ , with a high predominance of the former over the latter, thus indicating an oxygen-deficient MoO 3 film. From Rutherford backscattering spectroscopic analysis of the films, an average O/Mo atomic ratio of 2.9 was calculated, consistent with the XPS results. A combination of the XPS and RBS results and the data of other investigators on the oxidation of molybdenum suggests that the film is formed from MoO 2 and MoO 3 species desorbed from the Mo filament. The optical gap, E g , was determined from transmission UV-visible spectra of the films. An average E g value of 3.03 eV was found. The electrochromic properties of the films were investigated for Li + intercalation using an electrochemical cell. A coloration efficiency of 19.5 cm 2 /C at a wavelength of 700 nm was observed.

The bending beam method for measurements of stress in thin films deposited on an elastic substrate in the form of a thin stripe has been improved by the introduction of a laser beam deflection system and of a laser spot position detector. With this improvement, stress measurements have been performed in situ during the electrochemical reactions of palladium hydride formation and of valve metal anodic oxidation. Stress changes in the thin films of 107 N/m 2 can be measured with a time response better than ls. This allows the detection of rapid reactions (like H diffusion in a Pd thin film) and of the electrostriction effect even in anodic films with thickness below 20 nm.

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NonstoichiometriC, anhydrous NiO~ thin films were produced by sputtering. They can be bleached by means of hydrogen insertion equally fast and efficiently either in an electrochemical cell or in a gas chamber, as demonstrated in this work by using a Pd covered thin film electrode. The electrode mechanical stress and transmittance changes during H insertion and extraction, measured in situ, showed an increase in the compressive stress in the cathodic (bleaching) cycle

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