Derivation of surface structures from Fourier transforms of photoelectron diffraction data

1984 ◽  
Vol 30 (12) ◽  
pp. 7332-7335 ◽  
Author(s):  
M. Sagurton ◽  
E. L. Bullock ◽  
C. S. Fadley
Keyword(s):  
Diffraction Data ◽  
Fourier Transforms ◽  
Surface Structures ◽  
Photoelectron Diffraction

scholarly journals Holographic atomic images from surface and bulk W(110) photoelectron diffraction data

1999 ◽  
Vol 59 (8) ◽  
pp. 5857-5870 ◽  
Author(s):  
P. M. Len ◽  
J. D. Denlinger ◽  
E. Rotenberg ◽  
S. D. Kevan ◽  
B. P. Tonner ◽  
...  
Keyword(s):  
Diffraction Data ◽  
Photoelectron Diffraction

scholarly journals Direct determination of surface structures from photoelectron diffraction

1984 ◽  
Vol 2 (2) ◽  
pp. 847-851 ◽  
Author(s):  
J. J. Barton ◽  
C. C. Bahr ◽  
Z. Hussain ◽  
S. W. Robey ◽  
L. E. Klebanoff ◽  
...  
Keyword(s):  
Direct Determination ◽  
Surface Structures ◽  
Photoelectron Diffraction

scholarly journals A history of experimental phasing in macromolecular crystallography

2016 ◽  
Vol 72 (3) ◽  
pp. 293-295 ◽  
Author(s):  
Neil Isaacs
Keyword(s):  
Crystal Structures ◽  
Electron Density ◽  
Diffraction Data ◽  
Fourier Transforms ◽  
Macromolecular Crystallography ◽  
X Ray Diffraction ◽  
Crystal Lattices ◽  
X Ray ◽  
Experimental Phasing ◽  
History Of

It was just over a century ago that W. L. Bragg published a paper describing the first crystal structures to be determined using X-ray diffraction data. These structures were obtained from considerations of X-ray diffraction (Bragg equation), crystallography (crystal lattices and symmetry) and the scattering power of different atoms. Although W. H. Bragg proposed soon afterwards, in 1915, that the periodic electron density in crystals could be analysed using Fourier transforms, it took some decades before experimental phasing methods were developed. Many scientists contributed to this development and this paper presents the author's own perspective on this history. There will be other perspectives, so what follows isahistory, rather thanthehistory, of experimental phasing.

Investigation of the near-surface structures of polar InN films by chemical-state-discriminated hard X-ray photoelectron diffraction

2013 ◽  
Vol 102 (3) ◽  
pp. 031914 ◽  
Author(s):  
A. L. Yang ◽  
Y. Yamashita ◽  
M. Kobata ◽  
T. Matsushita ◽  
H. Yoshikawa ◽  
...  
Keyword(s):  
Chemical State ◽  
Surface Structures ◽  
Near Surface ◽  
X Ray ◽  
Photoelectron Diffraction

X-ray photoelectron studies of titanium in biotite and phlogopite

Clay Minerals ◽  
1980 ◽  
Vol 15 (3) ◽  
pp. 209-217 ◽  
Author(s):  
S. Evans ◽  
E. Raftery
Keyword(s):  
Single Crystals ◽  
Diffraction Data ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
Octahedral Sites

AbstractX-ray photoelectron diffraction data from single crystals of a biotite containing ∼1% Ti show that although this element is located entirely in octahedral sites, the Ti sites are not precisely equivalent to those of Mg and Fe. Comparisons of Ti 2p X-ray photoelectron spectra from two biotites and from two titaniferous phlogopites (∼0·3–·5% Ti) with those from Ti(II), Ti(III) and Ti(IV) oxides indicate that this element is present as Ti(III) rather than Ti(IV) in all four micas.

scholarly journals Multi-Solution Genetic Algorithm Approach to Surface Structure Determination Using Direct Methods

1997 ◽  
Vol 53 (6) ◽  
pp. 916-922 ◽  
Author(s):  
E. Landree ◽  
C. Collazo-Davila ◽  
L. D. Marks
Keyword(s):  
Genetic Algorithm ◽  
Diffraction Data ◽  
Structure Determination ◽  
Solution Space ◽  
Direct Methods ◽  
Search Method ◽  
Surface Structures ◽  
Genetic Algorithm Approach ◽  
Surface Diffraction ◽  
Algorithm Search

We show that it is possible to use a multi-solution genetic algorithm search method utilizing direct methods to solve surface structures from surface diffraction data. We suggest that the method is generally applicable and able to replace random searches of the solution space.

LEED crystallographic studies for the chemisorption of oxygen on the (100) surface of copper

1988 ◽  
Vol 66 (8) ◽  
pp. 2054-2062 ◽  
Author(s):  
H. C. Zeng ◽  
R. A. McFarlane ◽  
R. N. S. Sodhi ◽  
K. A. R. Mitchell
Keyword(s):  
Antiphase Domain ◽  
Structural Features ◽  
Copper Surface ◽  
Surface Structures ◽  
Photoelectron Diffraction ◽  
Low Energy Electron Diffraction ◽  
Domain Boundaries ◽  
Low Energy Electron ◽  
Structural Analogy ◽  
O Phase

Intensity analyses with low-energy electron diffraction (LEED) are reported for surface structures obtained by adsorbing submonolayer amounts of oxygen on the (100) surface of copper. It is found for chemisorption on the four-coordinate hollow sites that the correspondence between experimental and calculated intensity-versus-energy curves, for 10 diffracted beams, is slightly better for coplanar adsorption than for adsorption about 0.75 Å above the surface (the latter model is essentially as proposed previously by both SEXAFS and photoelectron diffraction). Nevertheless, in neither of these contrasting situations is the agreement sufficient to conclude that the structural analysis is complete. Evidence is presented that nearly coplanar chemisorption, in combination with a missing row model, can accommodate a number of structural features for this system, including the existence of the (2√2 × √2)45°−O phase, beam splittings resulting from antiphase domain boundaries, and the structural analogy noted in other studies between the (2√2 × √2)45°−O phase and the stepped nature of the (410) copper surface which can form by faceting in oxygen. Considerations of O–Cu surface bond lengths, guided by those in bulk Cu2O, suggest that additional lateral relaxations are likely in the topmost copper layer. This study provides no support for the O chemisorption occurring in tetrahedral-type sites.

scholarly journals SUePDF: a program to obtain quantitative pair distribution functions from electron diffraction data

2017 ◽  
Vol 50 (1) ◽  
pp. 304-312 ◽  
Author(s):  
Dung Trung Tran ◽  
Gunnar Svensson ◽  
Cheuk-Wai Tai
Keyword(s):  
Electron Diffraction ◽  
Electron Scattering ◽  
Diffraction Data ◽  
Amorphous Materials ◽  
Fourier Transforms ◽  
Distribution Functions ◽  
Electron Diffraction Data ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Pair Distribution Functions

SUePDFis a graphical user interface program written in MATLAB to achieve quantitative pair distribution functions (PDFs) from electron diffraction data. The program facilitates structural studies of amorphous materials and small nanoparticles using electron diffraction data from transmission electron microscopes. It is based on the physics of electron scattering as well as the total scattering methodology. A method of background modeling is introduced to treat the intensity tail of the direct beam, inelastic scattering and incoherent multiple scattering. Kinematical electron scattering intensity is scaled using the electron scattering factors. The PDFs obtained after Fourier transforms are normalized with respect to number density, nanoparticle form factor and the non-negativity of probability density.SUePDFis distributed as free software for academic users.

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