scholarly journals Molecular Dynamics Study on Structural Relaxation Processes in Amorphous Germanium

2017 ◽  
Vol 81 (2) ◽  
pp. 66-70
Author(s):  
Shigetaka Imabayashi ◽  
Manabu Ishimaru
Keyword(s):  
Molecular Dynamics ◽  
Structural Relaxation ◽  
Relaxation Processes ◽  
Amorphous Germanium

Decoupling of viscosity and relaxation processes in supercooled water: a molecular dynamics study with the TIP4P/2005f model

2017 ◽  
Vol 19 (3) ◽  
pp. 2124-2130 ◽  
Author(s):  
Emmanuel Guillaud ◽  
Samy Merabia ◽  
Dominique de Ligny ◽  
Laurent Joly
Keyword(s):  
Molecular Dynamics ◽  
Relaxation Time ◽  
Structural Relaxation ◽  
Supercooled Water ◽  
Water Model ◽  
Large Temperature ◽  
Relaxation Processes ◽  
Temperature Range ◽  
Self Diffusion ◽  
Structural Relaxation Time

We show that the TIP4P/2005f water model describes accurately the experimental viscosity and self-diffusion over a large temperature range. We then show the decoupling of viscosity and structural relaxation time in supercooled water.

scholarly journals Structural relaxation probed by resistance drift in amorphous germanium

2020 ◽  
Vol 7 (3) ◽  
pp. 036410
Author(s):  
Ning-Ning Dong ◽  
Jian-Gen Xu ◽  
Jin-Jiang Cui ◽  
Xiaodong Wang
Keyword(s):  
Structural Relaxation ◽  
Amorphous Germanium

Structural Relaxation Process in CuHfTi Amorphous Alloys

2009 ◽  
Vol 283-286 ◽  
pp. 533-538 ◽  
Author(s):  
Kazumasa Yamada ◽  
N. Shinagawa ◽  
M. Sogame ◽  
I.A. Figueroa ◽  
Hywel A. Davies ◽  
...  
Keyword(s):  
Activation Energy ◽  
Relaxation Process ◽  
Structural Relaxation ◽  
Amorphous Alloys ◽  
Melt Spinning ◽  
Amorphous Materials ◽  
Ternary Alloys ◽  
Relaxation Processes ◽  
Scanning Calorimetry ◽  
Structure Relaxation

The aim of this research is to clarify a quantitative evaluation in the structural relaxation processes focusing on the activation energy in Cu based amorphous alloys. The activation energy for structural relaxation process in a metal type amorphous CuHfTi ternary alloys, with cross sections of typically 0.03 mm x 2.0 mm, prepared by chill-block melt spinning has been investigated by Differential Scanning Calorimetry (DSC) with a cyclically heating technique. Activation energies for structural relaxation with a spatial quantity in amorphous materials have been discussed by use of a relaxed ratio function that depends on annealing temperature and time. In the present work, the distributions for the Activation Energy Spectrum (AES) were observed almost 152 kJmol-1 (1.58 eV). Another result has been also established that the “reversible” AES model energy distribution though the cyclically structure relaxation occurs even in amorphous Cu60Hf20Ti20 alloy.

scholarly journals Origin of the enhanced structural and reorientational relaxation rates in the presence of relatively weak dc electric fields

2004 ◽  
Vol 76 (1) ◽  
pp. 215-221 ◽  
Author(s):  
A. Vegiri
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Electric Fields ◽  
Structural Relaxation ◽  
Structural Changes ◽  
Common Mechanism ◽  
Weak Electric Field ◽  
Water Molecules ◽  
Relaxation Rates ◽  
Dynamics Simulations

The origin of the dramatic increase of the reorientational and structural relaxation rates of single water molecules in clusters of size N = 16, 32, and 64 at T = 200 K, under the influence of an external, relatively weak electric field (~0.5 107 V/cm) is examined through molecular dynamics simulations. The observed effect is attributed not to any profound structural changes, but to the increase of the size of the molecular cage. The response of water to an electric field in this range shows many similarities with the dynamics of water under low pressure. By referring to simulations and experiments from the literature, we show that in both cases the observed effects are dictated by a common mechanism.

Structural relaxation in Ag-Ni nanoparticles: Atomistic modeling away from equilibrium

2021 ◽  
Author(s):  
Florent Calvo
Keyword(s):  
Molecular Dynamics ◽  
Structural Relaxation ◽  
Rare Events ◽  
Metal Vapor ◽  
Silver Concentration ◽  
Atomistic Modeling ◽  
Ni Nanoparticles ◽  
Vapor Mixture ◽  
Chemical Ordering ◽  
Fast Cooling

The out-of-equilibrium structural relaxation of Ag-Ni nanoparticles containing about 1000--3000 atoms was investigated computationally by means of molecular dynamics trajectories in which the temperature is decreased gradually over hundreds of nanoseconds. At low silver concentration of 10--30\%, the evolution of chemical ordering in Ni$_{\rm core}$Ag$_{\rm shell}$ nanoparticles with different surface arrangements is found to proceed spontaneously and induce some rounding of the nickel core and its partial recristallization. Fast cooling of an initially hot metal vapor mixture was also considered, and it is shown to disfavor silver aggregation at the surface. Silver impurities are also occasionally produced but remain rare events under the conditions of our simulations.

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