scholarly journals A Comparison between Electron Crystal Scattering Potentials derived from X-ray Electron Densities and from Atom Muffin Tin Potentials

1985 ◽  
Vol 38 (3) ◽  
pp. 487 ◽  
Author(s):  
Andrew E Smith ◽  
DF Lynch

Two different forms of electron crystal potential are compared for the particular cases of aluminium and niobium diselenide. One of these is the solid-state muffin tin potential frequently used for band structure and low energy electron diffraction problems, and with its natural representation in real space. The other potential, derived from X-ray structure factors, is that most commonly used in electron microscopy structure determinations. It is expressed in terms of its Fourier coefficients and is accordingly a reciprocal space representation. Comparisons are carried out in both spaces. It is concluded that differences between the potentials are only minor and are mainly due to details in truncation and superposition.

2005 ◽  
Vol 483-485 ◽  
pp. 547-550 ◽  
Author(s):  
Konstantin V. Emtsev ◽  
Thomas Seyller ◽  
Lothar Ley ◽  
A. Tadich ◽  
L. Broekman ◽  
...  

We have investigated Si-rich reconstructions of 4H-SiC( 00 1 1 ) surfaces by means of low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy (XPS), and angleresolved ultraviolet photoelectron spectroscopy (ARUPS). The reconstructions of 4H-SiC( 00 1 1 ) were prepared by annealing the sample at different temperatures in a flux of Si. Depending on the temperature different reconstructions were observed: c(2×2) at T=800°C, c(2×4) at T=840°C. Both reconstructions show strong similarities in the electronic structure.


1992 ◽  
Vol 242 ◽  
Author(s):  
Andrew Freedman ◽  
Gary N. Robinson ◽  
Charter D. Stinespring

ABSTRACTDiamond (111) surfaces with the dehydrogenerated 2×1 reconstruction have been exposed to a beam of atomic fluorine at 300 K. The uptake of fluorine, as measured using X-ray photoelectron spectroscopy, is quite efficient and saturates at a coverage of less than a monolayer. Low energy electron diffraction patterns indicate that fluorine termination of the diamond surface produces a lxi bulk-like reconstruction in contrast to the disordered surface produced on the (100) surface.


1994 ◽  
Vol 299 ◽  
Author(s):  
Gary A. Gibson ◽  
Davis A. Lange ◽  
Charles M. Falco

AbstractWe have used Molecular Beam Epitaxy (MBE) to successfully grow films that are predominantly IrSi3 on both Si(111) and Si(100) substrates by codeposition of Si and Ir in a 3:1 ratio. Bragg-Brentano and Seemann-Bohlin x-ray diffraction reveal that polycrystalline IrSi3 films form as low as 450 °C. This is the lowest temperature yet reported for growth of this iridium silicide phase. These x-ray diffraction techniques, along with Transmission Electron Microscope (TEM) diffraction and in situ Low Energy Electron Diffraction (LEED), show that at higher deposition temperatures codeposition can form IrSi3 films on Si(111) that consist predominantly of a single epitaxial growth orientation. Ion beam channeling and x-ray rocking curves show that the epitaxial quality of IrSi3 films deposited on Si(111) is superior to that of IrSi3 films deposited on Si(100). We also present evidence for several new epitaxial IrSi3 growth modes on Si(111) and Si(100).


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