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Related papers: Activated mechanisms in amorphous silicon: an acti…

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From density functional calculations, we show that localized states stemming from defects or topological disorder exhibit an anomalously large electron-phonon coupling. We provide a simple analysis to explain the observation and perform a…

Disordered Systems and Neural Networks · Physics 2009-11-10 Raymond Atta-Fynn , Parthapratim Biswas , D. A. Drabold

We have performed an approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon (a-Si:H) using a molecular dynamics method. A 216 atom model for pure amorphous silicon (a-Si) has been employed as a…

Disordered Systems and Neural Networks · Physics 2009-10-31 Serge M. Nakhmanson , D. A. Drabold

The structural relaxation of pure amorphous silicon (a-Si) and hydrogenated amorphous silicon (a-Si:H) materials, that occurs during thermal annealing experiments, has been analysed by Raman spectroscopy and differential scanning…

Materials Science · Physics 2010-08-02 F. Kail , J. Farjas , P. Roura , C. Secouard , O. Nos , J. Bertomeu , F. Alzina , P. Roca i Cabarrocas

Using very long molecular dynamics simulation runs, temperature protocols spanning up to five orders of magnitude in time-scales are performed to investigate thermally activated structural relaxation in a model amorphous solid. The…

Materials Science · Physics 2017-10-11 P. M. Derlet , R. Maass

In this paper, we study several structural models of amorphous silicon, and discuss structural and electronic features common to all. We note spatial correlations between short bonds, and similar correlations between long bonds. Such…

Materials Science · Physics 2009-11-13 Yue Pan , Mingliang Zhang , D. A. Drabold

We have investigated the response of amorphous silicon (a-Si), in particular crystallization, to external mechanical shear deformations using classical molecular dynamics (MD) simulations and the empirical Environment Dependent Inter-atomic…

Materials Science · Physics 2015-05-28 Ali Kerrache , Normand Mousseau , Laurent J. Lewis

Locally, the atomic structure in well annealed amorphous silicon appears similar to that of crystalline silicon. We address here the question whether a point defect, specifically a vacancy, in amorphous silicon also resembles that in the…

Materials Science · Physics 2020-02-26 Andreas Pedersen , Laurent Pizzagalli , Hannes Jonsson

For several atomistic models of glass formers, at conditions below their glassy dynamics onset temperatures, ${T_\mathrm{o}}$, we use importance sampling of trajectory space to study the structure, statistics and dynamics of excitations…

Statistical Mechanics · Physics 2014-05-08 Aaron S. Keys , Lester O. Hedges , Juan P. Garrahan , Sharon C. Glotzer , David Chandler

The structural and electronic properties of amorphous silicon ($a$-Si) are investigated by first-principles calculations based on the density-functional theory (DFT), focusing on the intrinsic structural defects. By simulated melting and…

Materials Science · Physics 2017-10-11 Yoritaka Furukawa , Yu-ichiro Matsushita

Dynamics of jammed packings of soft athermal disks under finite-rate shear are studied by means of molecular dynamics simulations. Particularly, we investigate the spatial structures of stress drop events, which are expected to provide…

Soft Condensed Matter · Physics 2021-04-20 Shoichi Takahata , Norihiro Oyama , Kuniyasu Saitoh

We examine the structural relaxation of glassy materials at finite temperatures, considering the effect of activated rearrangements and long-range elastic interactions. Our three-dimensional mesoscopic relaxation model shows how the…

Soft Condensed Matter · Physics 2023-12-20 Gieberth Rodriguez-Lopez , Kirsten Martens , Ezequiel E. Ferrero

We use molecular dynamics computer simulations to study the equilibrium properties of the surface of amorphous silica. Two types of geometries are investigated: i) clusters with different diameters (13.5\AA, 19\AA, and 26.5\AA) and ii) a…

Statistical Mechanics · Physics 2009-10-31 Alexandra Roder , Walter Kob , Kurt Binder

The molecular dynamics method is applied to simulate the recrystallization of an amorphous/crystalline silicon interface. The atomic structure of the amorphous material is constructed with the method of Wooten, Winer, and Weaire. The…

Computational Physics · Physics 2011-07-07 Christophe Krzeminski , Quentin Brulin , V. Cuny , Emmanuel Lecat , Evelyne Lampin , Fabrizio Cleri

Amorphous silicon films prepared by electron beam evaporation have systematically and substantially greater atomic density for higher thickness, higher growth temperature, and slower deposition rate, reaching the density of crystalline Si…

Materials Science · Physics 2022-04-27 H. C. Jacks , M. Molina-Ruiz , M. H. Weber , J. J. Maldonis , P. M. Voyles , T. H. Metcalf , X. Liu , F. Hellman

We present a computational study of the electronic properties of amorphous SiO2. The ionic configurations used are the ones generated by an earlier molecular dynamics simulations in which the system was cooled with different cooling rates…

Disordered Systems and Neural Networks · Physics 2009-10-30 Thorsten Koslowski , Walter Kob , Katharina Vollmayr

Mechanical shear deformations lead, in some cases, to effects similar to those resulting from ion irradiation. Here we characterize the effects of shear velocity and temperature on amorphous silicon (\aSi) modelled using classical molecular…

Materials Science · Physics 2015-05-19 Ali Kerrache , Normand Mousseau , Laurent J. Lewis

We investigate a prominent vibrational feature in amorphous silica, the so-called boson peak, by means of molecular dynamics computer simulations. The dynamic structure factor S(q,nu) in the liquid, as well as in the glass state, scales…

Statistical Mechanics · Physics 2009-10-31 Jurgen Horbach , Walter Kob , Kurt Binder

Classical molecular-dynamics simulations have been carried out to investigate densification mechanisms in silicon dioxide thin films deposited on an amorphous silica surface, according to a simplified ion-beam assisted deposition (IBAD)…

Materials Science · Physics 2009-11-07 Alexis Lefevre , Laurent J. Lewis , Ludvik Martinu , Michael R. Wertheimer

Several static and dynamic properties of liquid silicon near melting have been determined from an orbital free {\em ab-initio} molecular dynamics simulation. The calculated static structure is in good agreement with the available X-ray and…

Materials Science · Physics 2015-06-25 A. Delisle , D. J. Gonzalez , M. J. Stott

Using the recently-proposed ``activation-relaxation technique'' for optimizing complex structures, we develop a structural model appropriate to a-GaAs which is almost free of odd-membered rings, i.e., wrong bonds, and possesses an almost…

Materials Science · Physics 2009-10-28 Normand Mousseau , Laurent J. Lewis