A NEW TECHNIQUE FOR SUBMONOLAYER NEXAFS : FLUORESCENCE YIELD AT THE CARBON K EDGE

摘要

Near Edge X-ray Absorption Fine Structure (NEXAFS) measurements at the C K edge are used to investigate linear hydrocarbon molecules on Cu (100) at 60 K. Four different detection modes are compared under the same experimental conditions : fluorescence yield (FY) , Auger electron yield, (AEY), partial electron yield (PEY) and total electron yield (TEY). Because of an increase of the edge jump ratio JR due to reduction in background intensity the fluorescence yield method is shown to be the most reliable. The values obtained for JR are : JR(FY) = 10, JR(AEY) = 0,6, JR(PEY) = 0,17 and JR(TEY) = 0,05. Submonolayer spectra of C2H2, C2H4, C2H6 on Cu (100) are presented.