RAMAN STUDIES OF PASSIVE FILMS ON IRON
ABSTRACT Raman spectroscopy has been applied to the in-situ study of thin oxide films grown on iron in different electrolytic solutions. The resulting films were artificially thicker than the usual passive films, from oxidation-reduction cycles, or from a polarization maintained for a long time (2 days). Their thickness was about 100–200 ° and their spectra compared to those of thermally grown oxide films having about the same thickness.
Summary. This paper presents some results of a case study about the characteristics of the interactions between pupils in groupworks, in the context of an innovative teaching experience of Physics at university level. Videorecordings were carried ou t during classes of the unit on Thermodynamics and some pupils from a focal group were interviewed. Analysis focused on group processes from the linguistic, social and cognitive perspectives. Results suggest that sharing cognitive processes by a group o f student, through reasoning and argumentation, may be an answer to the challenges of teaching practice at university level.