高分解能電子エネルギー損失分光におけるプローブ分散領域の運動学的解析 [in Japanese] Kinematic Analysis of a Dispersion Region Probed in High-Resolution Electron Energy-Loss Spectroscopy [in Japanese]
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High-resolution electron energy-loss spectroscopy (HREELS) is a powerful tool for observing an energy dispersion of low-energy surface excitation modes. In the specular-reflection geometry (SRG), a probed dispersion region determined kinematically depends upon the incident angle θ<SUB>0</SUB> and the incident energy <I>E</I><SUB>0</SUB>, while, in the off-specular geometry (OSG) it depends upon θ<SUB>0</SUB> and a scattered angle θ<SUB>S</SUB> adjusted by the analyzer position. With change in θ<SUB>0</SUB> and <I>E</I><SUB>0</SUB> in the SRG and with change in θ<SUB>0</SUB> and θ<SUB>S</SUB> in the OSG, we make a kinematic analysis of the probed dispersion region with special attention to its width. Our analysis shows that, with a grazing angle θ<SUB>0</SUB> fixed and with <I>E</I><SUB>0</SUB> or θ<SUB>S</SUB> varied, we can scan a sharply narrowed probed region on a wave number-angular frequency (<I>Q</I>-ω) plane to make an accurate observation of the energy dispersion of surface-excitation modes. An incident electron undergoes an image force, when it incidents on a surface of dielectric material. However, the image force is found to exert no substantial influence on the probed region even at grazing incidence.
Shinku 45(3), 200-203, 2002-03-20
The Vacuum Society of Japan