J. Phys. IV France 7 (1997) C2-249-C2-250
Anomalous Dispersion Effects in Glancing Angle XANES of Ultrathin FilmsD.T. Jiang and E.D. Crozier
Department of Physics. Simon Fraser University, Burnaby, BC Canada V5A 1S6
The XANES of a multilayer system obtained in the total reflection geometry can be distorted doe to anomalnis dispersion effects in the sample layers and in adjacent media. The former plays a negligible role in ultrathin film cases. The latter, caused by (he interference of the evanescent waves, cannot always be ignored. Calculated results of these effects are presented "and analytical expressions are provided in closed form. Experimental XANES data of a 8 monolayer Cn film grown on Ag(001) sofatrate are used to illustrate the theory. Filtered fluoresence XANES data are independent of angle and are not distorted. Total electron-yield and reflectivity data do depend on angle and are significantly distorted near the critical angle.
© EDP Sciences 1997