Small-cone method of directly forming atomic images from energy-dependent photoelectron-diffraction data

1995 ◽  
Vol 51 (20) ◽  
pp. 14549-14553 ◽  
Author(s):  
Huasheng Wu ◽  
G. J. Lapeyre
Keyword(s):  
Diffraction Data ◽  
Photoelectron Diffraction ◽  
Energy Dependent

Experimental Optimization for Imaging with Photoelectron Diffraction

1992 ◽  
Vol 295 ◽  
Author(s):  
J. G. Tobin ◽  
G. D. Waddill ◽  
Hua Li ◽  
S. Y. Tong
Keyword(s):  
Data Collection ◽  
Substantial Improvement ◽  
Single Image ◽  
Experimental Optimization ◽  
Photoelectron Diffraction ◽  
Holographic Imaging ◽  
Experimental Apparatus ◽  
Total Data ◽  
Energy Dependent ◽  
Collection Time

AbstractThe experimental apparatus and its optimization for holographic imaging with energy dependent photoelectron diffraction are described. A substantial improvement in data taking efficiency has resulted, allowing total data collection time to be reduced to about twelve hours for a single image-map.

scholarly journals Magnetic X-Ray Circular Dichroism in Spin-Polarized Photoelectron Diffraction

1994 ◽  
Vol 375 ◽  
Author(s):  
G. D. Waddill ◽  
J. G. Tobin ◽  
X. Guo ◽  
S. Y. Tong
Keyword(s):  
Magnetic Structure ◽  
Multiple Scattering ◽  
Analytical Procedure ◽  
Structural Determination ◽  
X Rays ◽  
Circularly Polarized ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
Spin Polarized ◽  
Energy Dependent

AbstractThe first structural determination with spin-polarized, energy-dependent photoelectron diffraction using circularly-polarized x-rays is reported for Fe films on Cu(001). Circularly-polarized x-rays produce spin-polarized photoelectrons from the Fe 2p doublet, and intensity asymmetries in the 2p3/2 level are observed. Fully spin-specific multiple scattering calculations reproduce the experimentally-determined energy and angular dependences. A new analytical procedure which focuses upon intensity variations due to spin-dependent diffraction is introduced. A sensitivity to local geometric and magnetic structure is demonstrated.

Surface Core-Level Photoelectron Diffraction of Surface Reconstructions

1994 ◽  
Vol 375 ◽  
Author(s):  
Eli Rotenberg ◽  
J. D. Denlinger ◽  
S. D. Kevan ◽  
B. P. Tonner
Keyword(s):  
High Energy ◽  
Core Level ◽  
High Energy Resolution ◽  
Photon Flux ◽  
Surface Geometry ◽  
Photoelectron Diffraction ◽  
Surface Reconstructions ◽  
Experimental Surface ◽  
Level Shifts ◽  
Energy Dependent

AbstractExperimental surface core-level shifts (SCLSs) aid in understanding the roles of altered electronic and screening properties at reconstructed semiconductor surfaces.1 Because of unresolved theoretical issues, the assignment of SCLSs has often remained controversial even though the surface geometry has been completely determined with traditional probes.Angular- and energy-dependent x-ray photoelectron diffraction (XPD) of each chemically resolved surface core-level electron can be used to discriminate the structure around each chemically shifted species. However, this technique requires tunability, high energy resolution to separate the SCLSs from the bulk core-levels, and high photon flux in order to gather large amounts of data in a reasonable time. Using the newly commissioned spectromicroscopy beamline 7.0 at the Advanced Light Source, we have acquired chemically-resolved XPD data for Si(111) 7×7 for several photon energies, and by examination of forward-focusing peaks we can draw tentative conclusions about the atomic origins of each core-level shifted peak.

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

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 Photoelectron Diffraction of Magnetic Ultrathin Films: Fe/Cu(001)

1990 ◽  
Vol 208 ◽  
Author(s):  
J. G. Tobin ◽  
M. K. Wagner ◽  
X.-O. Guo ◽  
S. Y. Tong.
Keyword(s):  
Synchrotron Radiation ◽  
Multiple Scattering ◽  
Cross Section ◽  
Ultrathin Films ◽  
Hollow Site ◽  
Nanoscale Structures ◽  
Photoelectron Diffraction ◽  
The Third ◽  
Energy Dependent ◽  
Fcc Structure

ABSTRACTThe preliminary results of an ongoing investigation of Fe/Cu(001) are presented here. Energy dependent photoelectron diffraction, including the spin-dependent variant using the multiplet split Fe 3s state, is being used to investigate the nanoscale structures formed by near-monolayer deposits of Fe onto Cu(001). Core-level photoemission from the Fe3p and Fe3s states has been generated using synchrotron radiation as the tunable excitation source. Tentatively, a comparison of the experimental Fe3p cross section measurements with multiple scattering calculations indicates that the Fe is in a fourfold hollow site with a spacing of 3.6Å between it and the atom directly beneath it, in the third layer. This is consistent with an FCC structure. The possibility of utilizing spin-dleendent photoelectron diffraction to investigate magnetic ultrathin films will be demonstrated, using our preliminary spectra of the multiplet-split Fe3s of near-monolayer Fe/Cu(001).

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