Ni(100), (111)清浄面およびH₂S,S吸着面からのAuger電子放出の角度分布

抄録

The polar and azimuthal angular distributions of 61 eV Ni-M_{2, 3}V V and 150 eV S-L_{2, 3} M_{2, 3}M_{2, 3} Auger electron emission from the Ni (100), (111) clean and H₂S, S-adsorbed surfaces have been investigated by means of the fluorescent screen-photomultiplier method developed. by the authors. The angular distribution of Ni Auger emission from a clean Ni single crystal surface shows a typical lobular profile. The results have been analyzed by a simple single-scattering diffraction model, The agreement between experimental and calculated results is. fairly good for the Ni Auger emission. Therefore, it is considered that the diffraction effect is significant in this case. However, in the case of Auger emission from the metallic bond, a small contribution due to inherent anisotropy should also be taken into consideration.
The angular distributions of S Auger electrons from the p(2×2) -H₂S, c(2×2)-H₂S, “pp(2×2)-S”, c(2×2)-S structures on Ni (100) surfaces have fundamentally similar anisotropic profiles, showing a marked peak at 45_??_50° from the surface normal to the plane [001] Az.. These results could hardly be interpreted only in terms of diffraction effects, and the possi-bility of inherent anisotropic emission of WVV Auger electrons might be suggested. The angular profiles of S Auger electrons from several adsorbed structures on Ni (111) surfaces represent an intermediate character between isotropic and cosine distributions.