Thermodynamic distribution functions associated to the isothermal phase transition in Langmuir monolayers

2006 ◽  
Vol 422 (1-3) ◽  
pp. 240-245 ◽  
Author(s):  
C.M. Rosetti ◽  
N. Wilke ◽  
B. Maggio
Keyword(s):  
Phase Transition ◽  
Langmuir Monolayers ◽  
Distribution Functions

scholarly journals Order Parameters, Orientational Distribution Functions and Heliconical Tilt Angles of Oligomeric Liquid Crystals

2019 ◽  
Author(s):  
Richard Mandle ◽  
John W. Goodby
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Tilt Angle ◽  
Order Parameter ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Thermal Evolution ◽  
Order Parameters ◽  
Distribution Functions ◽  
Orientational Distribution

We compare the order parameters, orientational distribution functions (ODF) and heliconical tilt angles of the TB phase exhibited by a liquid-crystalline dimer (CB7CB) to a tetramer (O47) and hexamer (O67) by SAXS/WAXS. Following the N-TB phase transition we find that all order parameters decrease, and while 〈P2 〉 remains positive 〈P4 〉 becomes negative. For all three materials the order parameter 〈P6 〉 is near zero in both phases. The ODF is sugarloaf-like in the nematic phase and volcano-like in the TB phase, allowing us to estimate the heliconical tilt angle of each material and its thermal evolution. The heliconical tilt angle appears to be largely independent of the material studied despite the differing number of mesogenic units.

Remarkable Difference of Phase Transition Behaviors Between Langmuir Monolayers and Aqueous Bilayer Vesicles of Oligopeptide-Carrying Lipids

2006 ◽  
Vol 6 (6) ◽  
pp. 1718-1730 ◽  
Author(s):  
Katsuhiko Ariga ◽  
Takashi Nakanishi ◽  
Shin-Ichi Kawanami ◽  
Takatoshi Kosaka ◽  
Jun-Ichi Kikuchi
Keyword(s):  
Phase Transition ◽  
Langmuir Monolayers ◽  
Remarkable Difference

Molecular Dynamic Simulation of Zigzag Silicon Carbide Nanoribbon

2021 ◽  
Vol 32 ◽  
Author(s):  
Hang Thi Thuy Nguyen
Keyword(s):  
Phase Transition ◽  
Molecular Dynamics ◽  
Silicon Carbide ◽  
Md Simulation ◽  
Structural Evolution ◽  
Order Type ◽  
Distribution Functions ◽  
Heating Process ◽  
Initial Model ◽  
First Order

The heating process of zigzag silicon carbide nanoribbon (SiCNR) is studied via molecular dynamics (MD) simulation. The initial model contained 10000 atoms is heating from 50K to 6000K to study the structural evolution of zigzag SiCNR. The melting point is defined at 4010K, the phase transition from solid to liquid exhibits the first-order type. The mechanism of structural evolution upon heating is studied based on the radiral distribution functions, coordination number, ring distributions, and angle distributions.

Study on the Phase Transition from Amorphous Phases to Crystalline TiSi2

1995 ◽  
Vol 402 ◽  
Author(s):  
H. G. Nam ◽  
Nam-Ihn Cho
Keyword(s):  
Phase Transition ◽  
Distribution Functions ◽  
Titanium Silicide ◽  
Atomic Ordering ◽  
Amorphous Phases ◽  
Si Substrates ◽  
Transmission Electron ◽  
Short Range Ordering ◽  
Silicide Compounds ◽  
Deposition Conditions

AbstractTitanium silicides were prepared by coevaporation of Ti and Si on Si substrates at intermediate substrate temperatures followed by high temperature annealing. Depending on the deposition conditions, transmission electron diffraction analyses revealed two different halo patterns from the as-deposited samples. Variations in the deposition conditions included substrate temperature, deposition rate, and film thickness. Radial distribution functions were calculated to estimate the short range ordering of the amorphous phases. The interatomic distances of all the titanium silicide compounds were also calculated in order to compare them with the atomic ordering of amorphous phases. Phase transition from these amorphous phases to the first crystalline silicide is discussed in terms of kinetic variations as well as the atomic ordering.

Kinetics of a structural phase transition in Langmuir monolayers studied using x‐ray diffraction

1989 ◽  
Vol 90 (4) ◽  
pp. 2393-2397 ◽  
Author(s):  
B. Lin ◽  
J. B. Peng ◽  
J. B. Ketterson ◽  
P. Dutta ◽  
B. N. Thomas ◽  
...  
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Langmuir Monolayers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Kinetics Of

Computer Simulation Model for First-Order Phase Transition Fluctuation Stage

2010 ◽  
Vol 297-301 ◽  
pp. 502-507 ◽  
Author(s):  
Anna Bondareva ◽  
Tatiana Levchenko ◽  
Galina I. Zmievskaya
Keyword(s):  
Phase Transition ◽  
Order Phase Transition ◽  
Ion Irradiation ◽  
Distribution Functions ◽  
Computer Simulation Model ◽  
First Order ◽  
Wiener Processes ◽  
First Order Phase Transition ◽  
First Order Phase ◽  
Lattice Locations

Ion irradiation of surfaces leads to blistering (vacancy-gaseous bubbles formation into crystal lattice) and/or nano-scale islands of thin cover formation. Stochastic model of first order phase transition at fluctuation stage is presented by superposition of Wiener processes of nuclei clustering and it’s Brownian motion. Solution of Ito-Stratonovich stochastic differential equations allows studying the evolution of distribution functions versus clusters sizes and relative lattice locations of nuclei.

scholarly journals Неравновесная кинетика начальной стадии фазового перехода

2020 ◽  
Vol 62 (1) ◽  
pp. 40
Author(s):  
Г.И. Змиевская
Keyword(s):  
Phase Transition ◽  
Transition Probability ◽  
Kinetic Equations ◽  
Elastic Interaction ◽  
Distribution Functions ◽  
Condensation Process ◽  
Stochastic Dynamic ◽  
Transition Probability Density ◽  
Temporal Structures ◽  
Non Equilibrium

Kinetic partial differential equations of Kolmogorov-Feller and Einstein-Smoluchowski equation with nonlinear coefficients are solved by a new, stable numerical methods. The theory of stochastic dynamic variables establishes the connection of the solution of Ito stochastic equations in the sense of Stratonovich for the trajectories of Wiener random processes with the transition probability density of these processes, or distribution functions of kinetic equations. The classical theory of nucleation (formation of nuclei of the first order phase transition) describes a non-equilibrium stage of the condensation process by a diffusion random process in the space of the size of the nuclei of the phase transition, when fluctuations affect the clustering of the nuclei. The model of formation of vacancy-gas defects (pores, blisters) in the crystal lattice, arising as a result of its irradiation by inert gas ions xenon, is supplemented by the consideration of Brownian motion of non-point lattice defects, occurring under the action of superposition of paired long-range potentials of indirect elastic interaction of pores between themselves and with the boundaries of the layers. Pores coordinates are changing at times of the order of 10 − 100 ms, sustainable algorithms for calculating which provide a self-consistent defnition spatial - temporal structures of porosity in the sample. According to calculations of 106 trajectories, non-equilibrium kinetic functions were found. Pores distribution in size and coordinates in the layers of the irradiated materials, they characterize the fluctuation instability the initial stage of the phase transition, they are estimated local stresses and porosity in the model volume.

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