Scaling of 6n-Fold Bond-Orientational Order Parameters in a Hexatic Liquid-Crystal Thin Film

1996 ◽  
Vol 76 (24) ◽  
pp. 4556-4559 ◽  
Author(s):  
Chia-Fu Chou ◽  
John T. Ho ◽  
S. W. Hui ◽  
V. Surendranath
Keyword(s):  
Thin Film ◽  
Liquid Crystal ◽  
Orientational Order ◽  
Order Parameters ◽  
Bond Orientational Order

scholarly journals Liquid Crystal Ordering in the Hexagonal Phase of Rod-Coil Diblock Copolymers

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1262
Author(s):  
Mikhail A. Osipov ◽  
Maxim V. Gorkunov ◽  
Alexander A. Antonov
Keyword(s):  
Liquid Crystal ◽  
Order Parameter ◽  
Density Functional ◽  
Diblock Copolymers ◽  
Microphase Separation ◽  
Hexagonal Phase ◽  
Orientational Order ◽  
Order Parameters ◽  
Copolymer Composition ◽  
Rigid Rod

Density functional theory of rod-coil diblock copolymers, developed recently by the authors, has been generalised and used to study the liquid crystal ordering and microphase separation effects in the hexagonal, lamellar and nematic phases. The translational order parameters of rod and coil monomers and the orientational order parameters of rod-like fragments of the copolymer chains have been determined numerically by direct minimization of the free energy. The phase diagram has been derived containing the isotropic, the lamellar and the hexagonal phases which is consistent with typical experimental data. The order parameter profiles as functions of temperature and the copolymer composition have also been determined in different anisotropic phases. Finally, the spatial distributions of the density of rigid rod fragments and of the corresponding orientational order parameter in the hexagonal phase have been calculated.

The local order and structural evolution of amorphous PdAg alloy during isothermal annealing under high pressure: A molecular dynamics study

2015 ◽  
Vol 93 (1) ◽  
pp. 7-13
Author(s):  
Fatih Ahmet Celik ◽  
Sefa Kazanc
Keyword(s):  
Molecular Dynamics ◽  
Isothermal Annealing ◽  
Orientational Order ◽  
Structural Evolution ◽  
Alloy System ◽  
Order Parameters ◽  
Dynamics Simulation ◽  
Model Alloy ◽  
Local Order ◽  
Bond Orientational Order

In this study, the local order and the structural evolution of the PdAg binary alloy system during the crystallization process from the amorphous phase under different pressures was investigated using the molecular dynamics simulation method. The structural development and phase transformation of the model alloy system for pressures of 0, 1, and 5 GPa are analysed based on variations of the radial distribution function, the bond orientational order parameters, and Honeycutt–Andersen bond-type index method. The simulation results showed that higher pressures favoured amorphous-type atomic clusters and had an important effect on the bond orientational order parameters of the model system of the transformation from amorphous state to stable crystal phase during the isothermal annealing.

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