Direct surface-structure analysis by the peak rotation in circularly polarized light photoelectron diffraction

Rotation of the forward-focusing peak positions in the circular dichroism in photoelectron diffraction (CDPD) pattern is discussed in detail. Based on this phenomenon a new method of direct analysis of three-dimensional surface structure is proposed. The direction of the forward focusing peaks in CDPD contains information not only of the direction but also of the distance between the source atom and the scatterer atoms. Thus the three-dimensional surface structure can be directly determined without any complicated calculation. A formula for the angular dependence of effective angular momentum, m*(θ), of photoelectron has been developed for the analysis. The typical accuracy in this analysis is around 0.25 Å, which is comparable to usual photoelectron diffraction analysis and is enough to make a starting model for more detailed analyses such as LEED.