Interactions, local order, and atomic-rearrangement kinetics in amorphous nickel-phosphorous alloys

1985 ◽  
Vol 32 (8) ◽  
pp. 5402-5411 ◽  
Author(s):  
Thomas A. Weber ◽  
Frank H. Stillinger
Keyword(s):  
Local Order ◽  
Atomic Rearrangement

scholarly journals The atomic rearrangement process in the copper-gold alloy Cu 3 Au

1936 ◽  
Vol 157 (890) ◽  
pp. 213-233 ◽  
Keyword(s):  
Critical Temperature ◽  
Specific Heat ◽  
High Temperatures ◽  
Energy Content ◽  
Relative Number ◽  
Local Order ◽  
Total Change ◽  
High Specific Heat ◽  
Degree Of Order ◽  
Atomic Rearrangement

When certain single-phase alloys are cooled from high temperatures they undergo transformations consisting of a change from a random distribution of atoms amongst the atomic sites to an ordered one. The thermodynamics of such transformations have been considered by Bragg and Williams and also by Bethe and Peierls; the former assume that the energy involved in any atomic interchange is directly proportional to the statistical degree of order (superlattice order) throughout the whole alloy crystal, whilst the latter consider that it depends only on the relative number of like and unlike atoms immediately surrounding the atoms concerned in the interchange (order of nearest neighbours). Both assumptions enable relations to be derived for the change in degree of order (as separately defined) with temperature under equilibrium conditions. These relations are then used to calculate the change in energy content produced as a result of the atomic rearrangement. According to the theory of Bragg and Williams, the superlattice order disappears entirely on heating the alloy through the critical temperature and the energy content is affected only by the ordering process below the critical temperature. The theory of Bethe predicts that, although superlattice order disappears at the critical temperature, a high degree of local order persists, which vanishes only at very high temperatures; an abnormally high specific heat is to be expected, therefore, even above the critical temperature. In the case of β brass (CuZn) both theories give practically the same result for the total change in internal energy below the critical temperature, which is in reasonable agreement with experimental measurement. Neither theory gives the correct rate of release of energy in the neighbourhood of the critical temperature, and it would appear that the final disappearance of superlattice order is more sudden than theory indicates. The specific heat is abnormally high above the critical temperature owing presumably to the presence of local order.

LOCAL ORDER IN THE EUTECTIC Mg.72 Zn.28 ALLOY

1985 ◽  
Vol 46 (C8) ◽  
pp. C8-81-C8-86 ◽  
Author(s):  
P. Andonov ◽  
P. Chieux
Keyword(s):  
Local Order

scholarly journals Detecting dark photons from atomic rearrangement in the galaxy

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
James Eiger ◽  
Michael Geller
Keyword(s):  
Dark Matter ◽  
Ground State ◽  
Bound State ◽  
Current Data ◽  
Dark Sector ◽  
Atomic Process ◽  
The Galaxy ◽  
Atomic States ◽  
Atomic Rearrangement

Abstract We study a new dark sector signature for an atomic process of “rearrangement” in the galaxy. In this process, a hydrogen-like atomic dark matter state together with its anti-particle can rearrange to form a highly-excited bound state. This bound state will then de-excite into the ground state emitting a large number of dark photons that can be measured in experiments on Earth through their kinetic mixing with the photon. We find that for DM masses in the GeV range, the dark photons have enough energy to pass the thresholds of neutrino observatories such as Borexino and Super-Kamiokande that can probe for our scenario even when our atomic states constitute a small fraction of the total DM abundance. We study the corresponding bounds on the parameters of our model from current data as well as the prospects for future detectors.

Monitoring local order in the liquid-X interface

2021 ◽  
pp. e1875076
Author(s):  
Linsey Nowack ◽  
Stuart A. Rice
Keyword(s):  
Local Order ◽  
X Interface

scholarly journals Interplay of local order and topology in the extended Haldane-Hubbard model

2021 ◽  
Vol 103 (3) ◽  
Author(s):  
Can Shao ◽  
Eduardo V. Castro ◽  
Shijie Hu ◽  
Rubem Mondaini
Keyword(s):  
Hubbard Model ◽  
Local Order ◽  
And Topology

Electronic Theory of Local Order

1956 ◽  
Vol 104 (2) ◽  
pp. 350-356 ◽  
Author(s):  
P. A. Flinn
Keyword(s):  
Local Order ◽  
Electronic Theory

scholarly journals Time-Dependent Diffusion Coefficients for Chaotic Advection due to Fluctuations of Convective Rolls

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 99 ◽  
Author(s):  
Kazuma Yamanaka ◽  
Takayuki Narumi ◽  
Megumi Hashiguchi ◽  
Hirotaka Okabe ◽  
Kazuhiro Hara ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Liquid Crystals ◽  
Diffusion Coefficients ◽  
Coarse Graining ◽  
Chaotic Advection ◽  
Time Dependent ◽  
Local Order ◽  
Weak Turbulence ◽  
Normal Diffusion ◽  
Convective Rolls

The properties of chaotic advection arising from defect turbulence, that is, weak turbulence in the electroconvection of nematic liquid crystals, were experimentally investigated. Defect turbulence is a phenomenon in which fluctuations of convective rolls arise and are globally disturbed while maintaining convective rolls locally. The time-dependent diffusion coefficient, as measured from the motion of a tagged particle driven by the turbulence, was used to clarify the dependence of the type of diffusion on coarse-graining time. The results showed that, as coarse-graining time increases, the type of diffusion changes from superdiffusion → subdiffusion → normal diffusion. The change in diffusive properties over the observed timescale reflects the coexistence of local order and global disorder in the defect turbulence.

Sign in / Sign up

Export Citation Format

Share Document