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

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.

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

PRECISION CALCULATION OF THE π-d SCATTERING LENGTH

2011 ◽  
Vol 26 (03n04) ◽  
pp. 589-591
Author(s):  
M. HOFERICHTER ◽  
V. BARU ◽  
C. HANHART ◽  
B. KUBIS ◽  
A. NOGGA ◽  
...  
Keyword(s):  
Virtual Photon ◽  
Charged Pion ◽  
Scattering Length ◽  
Coupling Constant ◽  
Hydrogen Atoms ◽  
Sum Rule ◽  
Pionic Hydrogen ◽  
Pion Nucleon ◽  
Using Data ◽  
Scattering Lengths

We present a calculation of the π-d scattering length in the framework of chiral perturbation theory (ChPT) with focus on virtual-photon effects. Using data on pionic deuterium and pionic hydrogen atoms, we extract the isoscalar and isovector pion–nucleon scattering lengths [Formula: see text] and [Formula: see text], as well as—via the Goldberger–Miyazawa–Oehme sum rule—the charged-pion–nucleon coupling constant [Formula: see text]

Remarks on the diffuse interstellar lines

1967 ◽  
Vol 31 ◽  
pp. 91-93 ◽  
Author(s):  
G. Herzberg
Keyword(s):  
Hydrogen Atoms ◽  
Interstellar Gas

It is suggested that the diffuse interstellar lines are produced in the interstellar gas by molecules consisting of a few hydrogen atoms and one other atom, such as CH4+ or NH4. Diffuseness of the lines is assumed to result from predissociation of these molecules.

SURFACE PLASMA SOURCE OF HYDROGEN ATOMS WITH AN ENERGY OF HUNDREDS eV

1979 ◽  
Vol 40 (C7) ◽  
pp. C7-479-C7-480 ◽  
Author(s):  
V. G. Dudnikov ◽  
G. I. Fiksel'
Keyword(s):  
Plasma Source ◽  
Surface Plasma ◽  
Hydrogen Atoms

H NMR Evidence for a Change in The Local Hydrogen Environment of Sites Associated with the Staebler-Wronski Effect in a-Si:H

2002 ◽  
Vol 715 ◽  
Author(s):  
T. Su ◽  
Robin Plachy ◽  
P. C. Taylor ◽  
S. Stone ◽  
G. Ganguly ◽  
...  
Keyword(s):  
Line Shape ◽  
Defect Density ◽  
Hydrogen Atoms ◽  
Hydrogen Environment ◽  
H Nmr ◽  
Line Shapes ◽  
Different Temperatures ◽  
Staebler Wronski Effect

AbstractWe study the H NMR line shapes of a sample of a-Si:H under several conditions: 1) as grown, 2) light-soaked for 600 hours, and 3) light-soaked followed by annealing at different temperatures. At T = 7 K, the NMR line shape of the sample after light soaking exhibits an additional doublet compared to that of the sample as-grown. This doublet is an indication of a closely separated hydrogen pair. The distance between the two hydrogen atoms is estimated to be about (2.3 ± 0.2) Å. The concentration of these hydrogen sites is estimated to be between 1017 and 1018 cm-3 consistent with ESR measurements of the defect density after light soaking. This doublet disappears after the sample is annealed at 200°C for 4 hours.

Adiabatic large polarons in anisotropic molecular crystals

2011 ◽  
Vol 35 (1) ◽  
pp. 15-27
Author(s):  
Zoran Ivić ◽  
Željko Pržulj
Keyword(s):  
Energy Transfer ◽  
Effective Mass ◽  
Molecular Crystals ◽  
Single Chain ◽  
Proper Understanding ◽  
One Dimensional ◽  
Interchain Coupling ◽  
Large Polaron ◽  
The One

Adiabatic large polarons in anisotropic molecular crystals We study the large polaron whose motion is confined to a single chain in a system composed of the collection of parallel molecular chains embedded in threedimensional lattice. It is found that the interchain coupling has a significant impact on the large polaron characteristics. In particular, its radius is quite larger while its effective mass is considerably lighter than that estimated within the one-dimensional models. We believe that our findings should be taken into account for the proper understanding of the possible role of large polarons in the charge and energy transfer in quasi-one-dimensional substances.

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