INVESTIGATION OF SOME PHYSICAL-PROPERTIES OF THIN-FILMS BY X-RAY REFLECTIVITY

X-ray reflectivity at glancing angles is a very sensitive method which can be applied to the study of very different kinds of physical probl ems involving ultra thin films. In this paper we show: first, how we h ave solved a problem which dates back over three centuries: the struct ure of the Newton black film, second, how to investigate thermally ind uced capillary waves on a Langmuir monolayer of amphiphilic molecules and, finally, how to determine, with a very high accuracy, the density of a thin film of silica.