DETERMINATION OF MULTILAYER RELAXATIONS OF THE Cu(210) STEPPED SURFACE BY CALCULATION OF LEED INTENSITIES

1999 ◽  
Vol 06 (05) ◽  
pp. 819-824 ◽  
Author(s):  
Y. P. GUO ◽  
K. C. TAN ◽  
A. T. S. WEE ◽  
C. H. A. HUAN
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Multiple Scattering ◽  
Scattering Theory ◽  
Multiple Scattering Theory ◽  
R Factor ◽  
Stepped Surface

In this report, we investigate the surface multilayer relaxation of clean Cu(210) by the Barbieri/Van Hove symmetrized automated tensor LEED calculation, based upon the multiple scattering theory. We have examined the change of Pendry R factor as a function of the structural and nonstructural variables in the calculation. The results show that a Rp factor of 0.20 can be achieved when the top 10 interlayer spacings of clean Cu(210) were optimized to experimental data using a muffin-tin radius of 1.217 Å and a muffin-tin zero of 8 eV. The first three interlayer spacings are d12=0.761± 0.04 Å, d23=0.759± 0.04 Å and d34=0.862± 0.03 Å, respectively (versus the bulk value of 0.807 Å). It therefore appears that the Cu(210) surface contracts to some extent, decreasing the surface roughness. The strain-induced multilayer relaxation of Cu(210) surface is discussed.

ELASTIC pd SCATTERING AT HIGH ENERGIES

1988 ◽  
Vol 03 (05) ◽  
pp. 1301-1319 ◽  
Author(s):  
V.M. BRAUN ◽  
L.G. DAKHNO ◽  
V.A. NIKONOV
Keyword(s):  
Experimental Data ◽  
Differential Cross Section ◽  
Multiple Scattering ◽  
Cross Section ◽  
Differential Cross ◽  
Scattering Theory ◽  
High Energy ◽  
Multiple Scattering Theory ◽  
High Energies

High energy differential pd cross section is calculated in the framework of the multiple scattering theory, inelastic correction included. Special attention is paid to the analysis of the calculation uncertainties. The results agree well with the experimental data obtained at ISR energies in the q2 range 0.06–1.05 (GeV/c) 2. The calculation accuracy is proved to be not worse than 10–20% at q2~0.2 (GeV/c) 2 and much better at small q2, namely, ~1% in the optical point. Prediction for the differential cross section at UNK energy E lab =3 TeV is given.

scholarly journals Experimental demonstration of negative refraction with 3D locally resonant acoustic metafluids

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benoit Tallon ◽  
Artem Kovalenko ◽  
Olivier Poncelet ◽  
Christophe Aristégui ◽  
Olivier Mondain-Monval ◽  
...  
Keyword(s):  
Experimental Data ◽  
Yield Stress ◽  
Multiple Scattering ◽  
Silicone Rubber ◽  
Acoustic Waves ◽  
Scattering Theory ◽  
Negative Refraction ◽  
Volume Fraction ◽  
Experimental Demonstration ◽  
Acoustic Beam

AbstractNegative refraction of acoustic waves is demonstrated through underwater experiments conducted at ultrasonic frequencies on a 3D locally resonant acoustic metafluid made of soft porous silicone-rubber micro-beads suspended in a yield-stress fluid. By measuring the refracted angle of the acoustic beam transmitted through this metafluid shaped as a prism, we determine the acoustic index to water according to Snell’s law. These experimental data are then compared with an excellent agreement to calculations performed in the framework of Multiple Scattering Theory showing that the emergence of negative refraction depends on the volume fraction $$\Phi$$ Φ of the resonant micro-beads. For diluted metafluid ($$\Phi =3\%$$ Φ = 3 % ), only positive refraction occurs whereas negative refraction is demonstrated over a broad frequency band with concentrated metafluid ($$\Phi =17\%$$ Φ = 17 % ).

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