Summary Abstract: Molecular dynamics studies of dynamical processes on the silicon {100} reconstructed surface

1987 ◽  
Vol 5 (4) ◽  
pp. 1905-1906 ◽  
Author(s):  
Donald W. Brenner ◽  
Barbara J. Garrison
Keyword(s):  
Molecular Dynamics ◽  
Dynamical Processes ◽  
Reconstructed Surface

Structural Properties of Iron Nitride on Cu(100): an Ab-initio Molecular Dynamics study

2011 ◽  
Vol 1290 ◽  
Author(s):  
Dodi Heryadi ◽  
Udo Schwingenschlögl
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Structural Properties ◽  
Nitride Layer ◽  
Dynamics Simulation ◽  
Ab Initio Molecular Dynamics ◽  
Iron Nitrides ◽  
Iron Nitride ◽  
Magnetic Storage ◽  
Reconstructed Surface

ABSTRACTDue to their potential applications in magnetic storage devices, iron nitrides have been a subject of numerous experimental and theoretical investigations. Thin films of iron nitride have been successfully grown on different substrates. To study the structural properties of a single monolayer film of FeN we have performed an ab-initio molecular dynamics simulation of its formation on a Cu(100) substrate. The iron nitride layer formed in our simulation shows a p4gm(2x2) reconstructed surface, in agreement with experimental results. In addition to its structural properties, we are also able to determine the magnetization of this thin film. Our results show that one monolayer of iron nitride on Cu(100) is ferromagnetic with a magnetic moment of 1.67μB.

scholarly journals Surrogate Models for Studying the Wettability of Nanoscale Natural Rough Surfaces Using Molecular Dynamics

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2770
Author(s):  
Lingru Zheng ◽  
Maja Rücker ◽  
Tom Bultreys ◽  
Apostolos Georgiadis ◽  
Miranda M. Mooijer-van den Heuvel ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Contact Angle ◽  
Surrogate Model ◽  
Surface Topology ◽  
Coarse Grained ◽  
Modeling Methodology ◽  
Static Contact ◽  
Nanoscale Topography ◽  
Reconstructed Surface ◽  
Dynamics Simulations

A molecular modeling methodology is presented to analyze the wetting behavior of natural surfaces exhibiting roughness at the nanoscale. Using atomic force microscopy, the surface topology of a Ketton carbonate is measured with a nanometer resolution, and a mapped model is constructed with the aid of coarse-grained beads. A surrogate model is presented in which surfaces are represented by two-dimensional sinusoidal functions defined by both an amplitude and a wavelength. The wetting of the reconstructed surface by a fluid, obtained through equilibrium molecular dynamics simulations, is compared to that observed by the different realizations of the surrogate model. A least-squares fitting method is implemented to identify the apparent static contact angle, and the droplet curvature, relative to the effective plane of the solid surface. The apparent contact angle and curvature of the droplet are then used as wetting metrics. The nanoscale contact angle is seen to vary significantly with the surface roughness. In the particular case studied, a variation of over 65° is observed between the contact angle on a flat surface and on a highly spiked (Cassie–Baxter) limit. This work proposes a strategy for systematically studying the influence of nanoscale topography and, eventually, chemical heterogeneity on the wettability of surfaces.

Molecular Dynamics Studies of the Adatom Induced Rearrangement of the Silicon {100} Surface

1987 ◽  
Vol 94 ◽  
Author(s):  
Donald W. Brenner ◽  
Barbara J. Garrison
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Critical Role ◽  
High Energy ◽  
Atomic Scale ◽  
Dynamics Simulation ◽  
Ion Channeling ◽  
Scale Models ◽  
Silicon Growth ◽  
Reconstructed Surface

ABSTRACTA molecular dynamics simulation of the silicon adatom induced rearrangement of the silicon {100} symmetric dimer reconstructed surface has been performed. Surface diffusion is proposed to play a critical role in the reordering of this surface which leads to good epitaxy while it plays much less of a role in the reordering induced by an amorphous overlayer. These results are used to provide atomic-scale models which are consistent with high-energy ion channeling/blocking and LEED studies by Gossman and Feldman of the initial stages of silicon growth on this surface.

Epitaxial growth of Si1−xGex on Si(100)2 × 1: A molecular-dynamics study

1992 ◽  
Vol 7 (10) ◽  
pp. 2817-2827 ◽  
Author(s):  
Stéphane Ethier ◽  
Laurent J. Lewis
Keyword(s):  
Molecular Dynamics ◽  
Epitaxial Growth ◽  
Experimental Studies ◽  
Theoretical Work ◽  
Effective Potentials ◽  
High Substrate ◽  
Reconstructed Surface ◽  
Dynamics Simulations ◽  
Substrate Temperatures

We use molecular-dynamics simulations to study the growth of pure Si, Si0.5Ge0.5, and pure Ge on the 2 × 1 reconstructed surface of Si(100) in a way appropriate to the fabrication of thin films by the method of molecular-beam epitaxy (MBE), namely sequential deposition of energetic atoms. The atoms interact with one another via effective potentials of the Stillinger–Weber form, with parameters adjusted such as to describe all possible types of triplet interactions. Motivated by numerous experimental studies of MBE-grown films, we investigate in particular the structure of the deposits as a function of substrate temperature. We find in all three cases that at low substrate temperatures, poorly ordered structures form, while at high substrate temperatures, epitaxial growth takes place. The presence of Ge limits the number of crystalline overlayers that form, even though it appears to favor a more-ordered structure in the initial stages of growth. For pure Ge epitaxy, in particular, only the first three layers are crystalline, after which growth appears to proceed by the formation of islands, reminiscent of the Stranski–Krastanow growth scheme, and in qualitative agreement with recent experimental and theoretical work. In all samples, annealing improves the quality of the films—at least when grown at sufficiently high substrate temperatures. The interdiffusion of the species at the substrate-deposit interface is also examined.

MOLECULAR DYNAMICS STUDY OF THE FRICTION PROPERTIES FOR A Ge TIP–SURFACE SYSTEM

2001 ◽  
Vol 08 (05) ◽  
pp. 581-586
Author(s):  
JUN CAI ◽  
JIAN-SHENG WANG
Keyword(s):  
Molecular Dynamics ◽  
Md Simulation ◽  
Microscopic Level ◽  
Atomic Configuration ◽  
Macroscopic Scale ◽  
Permanent Damage ◽  
Sliding Direction ◽  
Surface System ◽  
Reconstructed Surface ◽  
Sliding Distance

The friction between a Ge tip and its (001)-(2 × 1) reconstructed surface is investigated by molecular dynamics (MD) simulation. It is found that when the tip and the substrate approach each other closely enough, a wear occurs under slip-stick way. At the same time, it is also found that a permanent damage occurs when the tip advances perpendicularly to the dimer rows of the surface, while such damage is not observed when the tip moves parallelly to the dimer rows. This is different from the friction phenomena on a macroscopic scale. At the microscopic level, the resulting atomic configuration and the properties of friction force vs. sliding distance depend strongly on a sliding direction.

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