We report on the temperature dependence of optical response of pure bcc iron and CrNiAl steel. Ellipsometric spectra, covering the 1.4‐3.0 eV spectral range, have been obtained during temperature cycles reaching 650 °C in UHV chamber. Since the penetration depth of light is rather small and the data are sensitive to the quality of sample surfaces, we have examined polished, etched and annealed samples. We identify characteristic features of the temperature dependence, consisting in spectral shifts of interband transitions and a redistribution of spectral weight. We have also detected reproducible irreversible changes in the initial stages of annealing cycles when the samples are heated to at least 300 °C. With increasing temperature, we observe a pronounced reduction of the minority‐spin interband contribution. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

We present a comparative study of UV degradation of poly[methyl(phenyl)silane] (PMPSi) thin films on Si substrate in HV and in the air. When exposed to UV light with energies around 3.6 eV, the Si backbone scission occurs. The degradation rate is influenced by the presence of oxygen, which is bonded to the Si atoms following the backbone scission. In our experiments, the samples were placed in an HV chamber and ellipsometric spectra were continuously recorded in the 3.3–5.0 eV range. The combined tungsten (halogen)‐deuterium source ensuring a proper level of light intensity used for both exposition and measurement. During 100 hours exposures at atmospheric pressure, the PMPSi film degraded completely and its optical response did not change further. Degradation of the sample exposed in vacuum (at the pressure of 5 × 10–6 Pa) is slower and stops earlier. Ellipsometric technique allowed us to perform detailed studies of the degradation dynamics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)