The index of refraction of thin films deposited on an optical flat is obtained by comparison of the fringe system set up in the film with that in the air gap between the film and another optical flat. The use of the method is illustrated by application to films produced in high frequency discharge tubes. Films produced in Pyrex glass and quartz tubes are shown to be silica in the form of cristobalite. Films produced in polystyrene tubes prove to have an index of refraction that is very low and is a function of the thickness.
Determination of nickel by non-dispersive atomic fluorescence spectrometry using a graphite furnace atomizer and a high frequency discharge lamp.