scholarly journals Calculation of Diffraction Patterns Associated with Electron Irradiation Induced Amorphization of CuTi.

1990 ◽  
Vol 209 ◽  
Author(s):  
R. Devanathan ◽  
N. Q. Lam ◽  
M. J. Sabochick ◽  
P. Okamoto ◽  
M. Meshii

ABSTRACTA new approach that uses the multislice method in conjunction with molecular dynamics simulations to study electron irradiation induced amorphisation is presented. Diffraction patterns were calculated for CuTi and found to be more sensitive than the pair correlation function to the structural changes preceding amorphisation. The results from this approach and from a study of long range order are presented.

2013 ◽  
Vol 773 ◽  
pp. 380-385
Author(s):  
Dong Zhang ◽  
X.M. Gao ◽  
Xu Yang Xiao ◽  
Z.F. Cheng ◽  
J.H. Xia

The microscopic structure Cu46Zr46Al8 alloys were investigated by means of molecular dynamics simulations. This work gives the structure properties including partial pair-correlation function, pair analysis technique and Voronoi indices, and the temperature dependence. The simulated pair-correlation function is consistent well with the experimental one. We found that the the fractions of icosahedra and the distorted icosahedra increase with the decreasing temperature and become into the dominant clusters in the bulk metallic glass. At the meanwhile, we found that the icosahedra and the distorted icosahedra around Cu, Zr and Al are different. The Cu-center and Al-center icosahedra and the distorted icosahedra increase with the decreasing temperature, but The Zr-center icosahedra and the distorted icosahedra decrease with the decreasing temperature.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4876
Author(s):  
Shenshen Li ◽  
Jijun Xiao

In order to better understand the role of binder content, molecular dynamics (MD) simulations were performed to study the interfacial interactions, sensitivity and mechanical properties of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/2,4,6-trinitrotoluene (CL-20/TNT) based polymer-bonded explosives (PBXs) with fluorine rubber F2311. The binding energy between CL-20/TNT co-crystal (1 0 0) surface and F2311, pair correlation function, the maximum bond length of the N–NO2 trigger bond, and the mechanical properties of the PBXs were reported. From the calculated binding energy, it was found that binding energy increases with increasing F2311 content. Additionally, according to the results of pair correlation function, it turns out that H–O hydrogen bonds and H–F hydrogen bonds exist between F2311 molecules and the molecules in CL-20/TNT. The length of trigger bond in CL-20/TNT were adopted as theoretical criterion of sensitivity. The maximum bond length of the N–NO2 trigger bond decreased very significantly when the F2311 content increased from 0 to 9.2%. This indicated increasing F2311 content can reduce sensitivity and improve thermal stability. However, the maximum bond length of the N–NO2 trigger bond remained essentially unchanged when the F2311 content was further increased. Additionally, the calculated mechanical data indicated that with the increase in F2311 content, the rigidity of CL-20/TNT based PBXs was decrease, the toughness was improved.


2013 ◽  
Vol 683 ◽  
pp. 348-352
Author(s):  
J.H. Xia ◽  
Zheng Fu Cheng ◽  
Xu Yang Xiao

The structural transitions of Ag965clusters during two different quenching processes (Q1:1.0×1014K/s, Q2: 1.0×1012K/s) were studied using molecular dynamics simulations. This work gives the structure properties including the variations with temperature of pair-correlation function, bond-angle distribution function, bond pairs and bond orientational order parameters in both rapid quenching processes. Our results indicated that the liquid Ag965 was frozen into amorphous structure at 100 K under the quenching condition Q1. While the liquid Ag965transformed to hexagonal close-packed (hcp) phase at the temperature 100 K under the quenching condition Q2.These instructions give you basic guidelines for preparing papers for conference proceedings.


1992 ◽  
Vol 291 ◽  
Author(s):  
Susanne M. Lee ◽  
Carol G. Hoover ◽  
Jeffrey S. Kallman ◽  
William G. Hoover ◽  
Anthony J. De Groot ◽  
...  

ABSTRACTWe study nanoindentation of silicon using nonequilibrium molecular dynamics simulations with up to a million particles. Both crystalline and amorphous silicon samples are considered. We use computational diffraction patterns as a diagnostic tool for detecting phase transitions resulting from structural changes. Simulations of crystalline samples show a transition to the amorphous phase in a region a few atomic layers thick surrounding the lateral faces of the indentor, as has been suggested by experimental results. Our simulation results provide estimates for the yield strength (nanohardness) of silicon for a range of temperatures.


2013 ◽  
Vol 401-403 ◽  
pp. 708-712
Author(s):  
Jian Hong Xia ◽  
Xue Mei Gao ◽  
Zheng Fu Cheng ◽  
Xu Yang Xiao

The structural transitions of the rapidly cooled Ti75Al25under high pressures were studied by using molecular dynamics simulations. This work gives the structural properties, including the potential energy, pair-correlation function, Honeycutt-Andersen (HA) and Voronoi indices, and temperature dependence. Our results indicated that the liquid Ti75Al25was frozen into glass state at the temperature about 300 K under different pressures during the same quenching processes. With increasing of pressure, the glass transformation temperature (Tg) become high. The icosahedral and defect icosahedral clusters increase as the temperature decreases under different pressures. But the icosahedral cluster increases with the increasing pressure and defect icosahedral clusters keeps invariability at 300 K.


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