Scattering length and effective range in two dimensions: application to adsorbed hydrogen atoms

1984 ◽  
Vol 17 (3) ◽  
pp. 595-598 ◽  
Author(s):  
B J Verhaar ◽  
J P H W van den Eijnde ◽  
M A J Voermans ◽  
M M J Schaffrath
Keyword(s):  
Scattering Length ◽  
Two Dimensions ◽  
Effective Range ◽  
Adsorbed Hydrogen ◽  
Hydrogen Atoms

scholarly journals THEORY OF COMPLEX SCATTERING LENGTHS

2001 ◽  
Vol 15 (03) ◽  
pp. 105-109
Author(s):  
M. S. HUSSEIN
Keyword(s):  
Scattering Length ◽  
Effective Range ◽  
Low Energies ◽  
T Matrix ◽  
Scattering Lengths ◽  
New Equation ◽  
Molecule Interaction ◽  
Complex Atom

We derive a generalized Low equation for the T-matrix appropriate for complex atom–molecule interaction. The properties of this new equation at very low energies are studied and the complex scattering length and effective range are derived.

A systematic neutron reflectometry study on hydrogen absorption in thin Mg1-xAlx alloy films Special issue on Neutron Scattering in Canada.

2010 ◽  
Vol 88 (10) ◽  
pp. 723-728 ◽  
Author(s):  
H. Fritzsche ◽  
E. Poirier ◽  
J. Haagsma ◽  
C. Ophus ◽  
E. Luber ◽  
...  
Keyword(s):  
Hydrogen Absorption ◽  
Scattering Length ◽  
Catalyst Layer ◽  
Neutron Reflectometry ◽  
Hydrogen Distribution ◽  
Hydrogen Atoms ◽  
Alloy Films ◽  
Negative Scattering Length ◽  
Insight Into ◽  
Optimum Alloy

In this article, we show how neutron reflectometry (NR) can provide deep insight into the absorption and desorption properties of commercially promising hydrogen storage materials. NR benefits from the large negative scattering length of hydrogen atoms, which changes the reflectivity curve substantially, so that NR can determine not only the total amount of stored hydrogen but also the hydrogen distribution along the film normal, with nanometer resolution. To use NR, the samples must have smooth surfaces, and the film thickness should range between 10 and 200 nm. We performed a systematic study on thin Mg1–xAlx alloy films (x = 0.2, 0.3, 0.4, 0.67) capped with a Pd catalyst layer. Our NR experiments showed that Mg0.7Al0.3 is the optimum alloy composition with the highest amount of stored hydrogen and the lowest desorption temperature. All the thin films expand by about 20% because of hydrogen absorption, and the hydrogen is stored only in the MgAl layer with no hydrogen content in the Pd layer.

scholarly journals Effective Potential for Ultracold Atoms at the Zero Crossing of a Feshbach Resonance

2012 ◽  
Vol 2012 ◽  
pp. 1-9
Author(s):  
N. T. Zinner
Keyword(s):  
Effective Potential ◽  
Feshbach Resonance ◽  
Cold Atoms ◽  
Particle Number ◽  
Scattering Length ◽  
Order Effect ◽  
Effective Range ◽  
Effective Range Expansion ◽  
Zero Crossing ◽  
Bose Einstein

We consider finite-range effects when the scattering length goes to zero near a magnetically controlled Feshbach resonance. The traditional effective-range expansion is badly behaved at this point, and we therefore introduce an effective potential that reproduces the full T-matrix. To lowest order the effective potential goes as momentum squared times a factor that is well defined as the scattering length goes to zero. The potential turns out to be proportional to the background scattering length squared times the background effective range for the resonance. We proceed to estimate the applicability and relative importance of this potential for Bose-Einstein condensates and for two-component Fermi gases where the attractive nature of the effective potential can lead to collapse above a critical particle number or induce instability toward pairing and superfluidity. For broad Feshbach resonances the higher order effect is completely negligible. However, for narrow resonances in tightly confined samples signatures might be experimentally accessible. This could be relevant for suboptical wavelength microstructured traps at the interface of cold atoms and solid-state surfaces.

Inactive step-edge Pt atoms boost oxygen reduction reaction by activating adsorbed hydrogen atoms

2020 ◽  
Vol 504 ◽  
pp. 144434 ◽  
Author(s):  
Na Cheng ◽  
Ling Zhang ◽  
Yuhang Li ◽  
Liyuan Chen ◽  
Hao Jiang ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Reduction Reaction ◽  
Step Edge ◽  
Adsorbed Hydrogen ◽  
Hydrogen Atoms

Dependence of the scattering length for hydrogen atoms on effective mass

2009 ◽  
Vol 56 (2) ◽  
pp. 181-188 ◽  
Author(s):  
M. J. Jamieson ◽  
A. S.C. Cheung ◽  
H. Ouerdane
Keyword(s):  
Effective Mass ◽  
Scattering Length ◽  
Hydrogen Atoms

Hydrogen Adsorption of Ruthenium: Isosteres of Solubility of Adsorbed Hydrogen

1998 ◽  
Vol 513 ◽  
Author(s):  
S. Yu. Zaginaichenko ◽  
Z. A. Matysina ◽  
D. V. Schur ◽  
V. K. Pishuk
Keyword(s):  
Phase Transition ◽  
Free Energy ◽  
Theoretical Investigation ◽  
State Transition ◽  
Hydrogen Adsorption ◽  
Adsorbed Hydrogen ◽  
Hydrogen Atoms ◽  
Hexagonal Close Packed ◽  
The Face ◽  
Pressure Hydrogen

ABSTRACTThe theoretical investigation of solubility isosteres of adsorbed hydrogen has been performed for free face (0001) of crystals with hexagonal close-packed lattice A3 of Mg type. The face free energy has been calculated and its dependence on temperature, pressure, hydrogen concentration and character of hydrogen atoms distribution over surface interstitial sites of different type has been defined. The equations of thermodynamic equilibrium and solubility of adsorbed hydrogen have been defined. The plots of isosteres in the region of phase transition from isotropic to anisotropic state have been constructed and it has been established that in anisotropic state the order in distribution of hydrogen atoms over interstitial sites of different type must become apparent. Comparison of the theoretical isosteres with experimental for ruthenium has been carried out, the isotropic-anisotropic state transition can stipulate a stepwise and break-like change in isosteres.

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