Low Energy Photoelectron Holography on Gaas

1992 ◽  
Vol 295 ◽  
Author(s):  
R. Denecke ◽  
R. Eckstein ◽  
L. Ley ◽  
A. Bocquet ◽  
J. Riley ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Kinetic Energy ◽  
Single Scattering ◽  
Real Space ◽  
Low Energy ◽  
Space Images ◽  
Photoelectron Diffraction ◽  
Diffraction Patterns

AbstractFor GaAs (001) and (III) we have measured the photoelectron diffraction patterns at a kinetic energy of 86 eV. We applied an extended Fourier-transform algorithm to the (001) data to obtain real space images. The origin of structures in these images not representing atomic positions is investigated with the help of single scattering calculations

Experimental and theoretical low-energy photoelectron diffraction study of the W(001) surface: Adequacy of a single scattering model

1987 ◽  
Vol 185 (3) ◽  
pp. L527-L533 ◽  
Author(s):  
D. Sebilleau ◽  
M.C. Desjonqueres ◽  
D. Chauveau ◽  
C. Guillot ◽  
J. Lecante ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Single Scattering ◽  
Low Energy ◽  
Scattering Model ◽  
Photoelectron Diffraction

Electron Holography at Atomic Dimensions

1997 ◽  
Vol 3 (S2) ◽  
pp. 1169-1170
Author(s):  
Hannes Lichte
Keyword(s):  
Phase Contrast ◽  
Real Space ◽  
Electron Holography ◽  
Contrast Transfer Function ◽  
Space Images ◽  
Transmission Electron ◽  
Electron Image ◽  
Final Electron ◽  
Diffraction Patterns ◽  
Better Than

Many of the problems of transmission electron microscopy (TEM) are due to the fact that wave optics which governs the interaction of electrons with the specimen and the imaging process definitely is brought to an end with the detection of the final electron image. Unfortunately, resolution is limited by an increasing number of aberrations. Furthermore, wave optical tools in the electron microscope which are needed for example to produce phase contrast better than that given by the phase contrast transfer function, for distinction of amplitude contrast and phase contrast, or to measure phases in Fourier space, are only poorly developed. Since subsequent image processing of electron diffraction patterns or real space images can never compensate for the loss of phase information, the phase has to be recorded also, i.e. one has to work holographically to collect and reconstruct all data of the object structure.

Experimental and theoretical low-energy photoelectron diffraction study of the W(001) surface: Adequacy of a single scattering model

1987 ◽  
Vol 185 (3) ◽  
pp. L527-L533 ◽  
Author(s):  
D. Sebilleau ◽  
M.C. Desjonqueres ◽  
D. Chauveau ◽  
C. Guillot ◽  
J. Lecante ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Single Scattering ◽  
Low Energy ◽  
Scattering Model ◽  
Photoelectron Diffraction

X-RAY PHOTOELECTRON DIFFRACTION STUDY OF A LONG-RANGE-ORDERED ACETATE LAYER ON Ni(110)

2000 ◽  
Vol 07 (01n02) ◽  
pp. 25-36 ◽  
Author(s):  
M. NOWICKI ◽  
A. EMUNDTS ◽  
J. WERNER ◽  
G. PIRUG ◽  
H. P. BONZEL
Keyword(s):  
Room Temperature ◽  
Solid Angle ◽  
Single Scattering ◽  
Real Space ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
Acetate Complex ◽  
Cluster Calculations ◽  
Model Layer ◽  
Good Agreement

An investigation of acetic acid adsorption on Ni(110) at room temperature by LEED and X-ray photoelectron diffraction reveals a well-ordered c(2 × 2) acetate overlayer with a molecular coverage near 0.5. Large solid angle maps of angle-resolved C 1s and O 1s intensities from this layer show intense maxima due to electron forward scattering by nearby atoms, either of the same acetate or of neighboring acetate species. The data provide strong evidence for acetate in a bidentate configuration, bonded through both oxygen atoms to the surface and aligned along the [Formula: see text] surface azimuth. A real space model for the c(2 × 2) acetate layer has been derived and single scattering cluster calculations for this model layer have been carried out for C 1s and O 1s emissions. Allowing for changes in intramolecular bond length of the acetate relative to those in a Ni-acetate complex, good agreement between experimental and theoretical C 1s and O 1s distributions was obtained.

Inelastic Electron Scattering from Valence Electrons in Aluminum

1976 ◽  
Vol 34 ◽  
pp. 462-463
Author(s):  
P. E. Batson ◽  
C. H. Chen ◽  
J. Silcox
Keyword(s):  
Electron Scattering ◽  
Single Scattering ◽  
Three Dimensions ◽  
Inelastic Electron ◽  
Weak Beam ◽  
Scattering Spectrum ◽  
Valence Electrons ◽  
Diffraction Patterns ◽  
Electronic Scattering

We wish to report in this paper measurements of the inelastic scattering component due to the collective excitations (plasmons) and single particlehole excitations of the valence electrons in Al. Such scattering contributes to the diffuse electronic scattering seen in electron diffraction patterns and has recently been considered of significance in weak-beam images (see Gai and Howie) . A major problem in the determination of such scattering is the proper correction for multiple scattering. We outline here a procedure which we believe suitably deals with such problems and report the observed single scattering spectrum.In principle, one can use the procedure of Misell and Jones—suitably generalized to three dimensions (qx, qy and #x2206;E)--to derive single scattering profiles. However, such a computation becomes prohibitively large if applied in a brute force fashion since the quasi-elastic scattering (and associated multiple electronic scattering) extends to much larger angles than the multiple electronic scattering on its own.

Comparison of Calculated and Recorded Electron Energy-Loss Spectra of Aluminium and Carbon

1990 ◽  
Vol 48 (2) ◽  
pp. 64-65
Author(s):  
L. Reimer ◽  
R. Oelgeklaus
Keyword(s):  
Fourier Transform ◽  
Energy Loss ◽  
Electron Energy ◽  
Rotational Symmetry ◽  
Mean Free Path ◽  
Single Scattering ◽  
Specimen Thickness ◽  
Two Dimensional ◽  
Image Position ◽  
Electron Energy Loss

Quantitative electron energy-loss spectroscopy (EELS) needs a correction for the limited collection aperture α and a deconvolution of recorded spectra for eliminating the influence of multiple inelastic scattering. Reversely, it is of interest to calculate the influence of multiple scattering on EELS. The distribution f(w,θ,z) of scattered electrons as a function of energy loss w, scattering angle θ and reduced specimen thickness z=t/Λ (Λ=total mean-free-path) can either be recorded by angular-resolved EELS or calculated by a convolution of a normalized single-scattering function ϕ(w,θ). For rotational symmetry in angle (amorphous or polycrystalline specimens) this can be realised by the following sequence of operations :(1)where the two-dimensional distribution in angle is reduced to a one-dimensional function by a projection P, T is a two-dimensional Fourier transform in angle θ and energy loss w and the exponent -1 indicates a deprojection and inverse Fourier transform, respectively.

Sign in / Sign up

Export Citation Format

Share Document