scholarly journals Role of hydrodynamics in liquid–liquid transition of a single-component substance

2020 ◽  
Vol 117 (9) ◽  
pp. 4471-4479 ◽  
Author(s):  
Kyohei Takae ◽  
Hajime Tanaka
Keyword(s):  
Liquid State ◽  
Order Parameter ◽  
Theoretical Description ◽  
Single Component ◽  
Degree Of Freedom ◽  
Domain Growth ◽  
Liquid Transition ◽  
Characteristic Features ◽  
Phase Ordering ◽  
Liquid States

Liquid–liquid transition (LLT) is an unconventional transition between two liquid states in a single-component system. This phenomenon has recently attracted considerable attention not only because of its counterintuitive nature but also since it is crucial for our fundamental understanding of the liquid state. However, its physical understanding has remained elusive, particularly of the critical dynamics and phase-ordering kinetics. So far, the hydrodynamic degree of freedom, which is the most intrinsic kinetic feature of liquids, has been neglected in its theoretical description. Here we develop a Ginzburg–Landau-type kinetic theory of LLT taking it into account, based on a two-order parameter model. We examine slow critical fluctuations of the nonconserved order parameter coupled to the hydrodynamic degree of freedom in equilibrium. We also study the nonequilibrium process of LLT. We show both analytically and numerically that domain growth becomes faster (slower), depending upon the density decrease (increase) upon the transition, as a consequence of hydrodynamic flow induced by the density change. The coupling between nonconserved order parameter and hydrodynamic interaction results in anomalous domain growth in both nucleation-growth–type and spinodal-decomposition–type LLT. Our study highlights the characteristic features of hydrodynamic fluctuations and phase ordering during LLT under complex interplay among conserved and nonconserved order parameters and the hydrodynamic transport intrinsic to the liquid state.

scholarly journals Polyamorphism Mirrors Polymorphism in the Liquid–Liquid Transition of a Molecular Liquid

2020 ◽  
Author(s):  
Finlay Walton ◽  
John Bolling ◽  
Andrew Farrell ◽  
Jamie MacEwen ◽  
Christopher Syme ◽  
...  
Keyword(s):  
Order Parameter ◽  
Supercooled Liquid ◽  
Supercooled Liquids ◽  
Molecular Packing ◽  
Single Component ◽  
Triphenyl Phosphite ◽  
Amorphous Phases ◽  
Geometrically Frustrated ◽  
Intimate Connection ◽  
Liquid Transition

Liquid-liquid transitions between two amorphous phases in a single-component liquid (polyamorphism) have defied explanation and courted controversy. All known examples of liquid–liquid transitions have been observed in the supercooled liquid suggesting an intimate connection with vitrification and locally favored structures inhibiting crystallization. However, there is precious little information about the local molecular packing in supercooled liquids meaning that the order parameter of the transition is still unknown. Here, we investigate the liquid–liquid transition in triphenyl phosphite and show that it is caused by the competition between liquid structures that mirror two crystal polymorphs. The liquid–liquid transition is found to be between a geometrically frustrated liquid to a dynamically frustrated glass. These results indicate a general link between polymorphism and polyamorphism and will lead to a much greater understanding of the physical basis of liquid–liquid transitions and allow the discovery of other examples.

scholarly journals Polyamorphism Mirrors Polymorphism in the Liquid–Liquid Transition of a Molecular Liquid

2019 ◽  
Author(s):  
Finlay Walton ◽  
John Bolling ◽  
Andrew Farrell ◽  
Jamie MacEwen ◽  
Christopher Syme ◽  
...  
Keyword(s):  
Order Parameter ◽  
Supercooled Liquid ◽  
Supercooled Liquids ◽  
Molecular Packing ◽  
Single Component ◽  
Triphenyl Phosphite ◽  
Amorphous Phases ◽  
Geometrically Frustrated ◽  
Intimate Connection ◽  
Liquid Transition

Liquid-liquid transitions between two amorphous phases in a single-component liquid (polyamorphism) have defied explanation and courted controversy. All known examples of liquid–liquid transitions have been observed in the supercooled liquid suggesting an intimate connection with vitrification and locally favored structures inhibiting crystallization. However, there is precious little information about the local molecular packing in supercooled liquids meaning that the order parameter of the transition is still unknown. Here, we investigate the liquid–liquid transition in triphenyl phosphite and show that it is caused by the competition between liquid structures that mirror two crystal polymorphs. The liquid–liquid transition is found to be between a geometrically frustrated liquid to a dynamically frustrated glass. These results indicate a general link between polymorphism and polyamorphism and will lead to a much greater understanding of the physical basis of liquid–liquid transitions and allow the discovery of other examples.

scholarly journals Polyamorphism Mirrors Polymorphism in the Liquid–Liquid Transition of a Molecular Liquid

2020 ◽  
Author(s):  
Finlay Walton ◽  
John Bolling ◽  
Andrew Farrell ◽  
Jamie MacEwen ◽  
Christopher Syme ◽  
...  
Keyword(s):  
Order Parameter ◽  
Supercooled Liquid ◽  
Supercooled Liquids ◽  
Molecular Packing ◽  
Single Component ◽  
Triphenyl Phosphite ◽  
Amorphous Phases ◽  
Geometrically Frustrated ◽  
Intimate Connection ◽  
Liquid Transition

Liquid-liquid transitions between two amorphous phases in a single-component liquid (polyamorphism) have defied explanation and courted controversy. All known examples of liquid–liquid transitions have been observed in the supercooled liquid suggesting an intimate connection with vitrification and locally favored structures inhibiting crystallization. However, there is precious little information about the local molecular packing in supercooled liquids meaning that the order parameter of the transition is still unknown. Here, we investigate the liquid–liquid transition in triphenyl phosphite and show that it is caused by the competition between liquid structures that mirror two crystal polymorphs. The liquid–liquid transition is found to be between a geometrically frustrated liquid to a dynamically frustrated glass. These results indicate a general link between polymorphism and polyamorphism and will lead to a much greater understanding of the physical basis of liquid–liquid transitions and allow the discovery of other examples.

scholarly journals Order-parameter scaling in fluctuation-dominated phase ordering

2016 ◽  
Vol 93 (1) ◽  
Author(s):  
Rajeev Kapri ◽  
Malay Bandyopadhyay ◽  
Mustansir Barma
Keyword(s):  
Order Parameter ◽  
Phase Ordering

scholarly journals Microscopic identification of the order parameter governing liquid–liquid transition in a molecular liquid

2015 ◽  
Vol 112 (19) ◽  
pp. 5956-5961 ◽  
Author(s):  
Ken-ichiro Murata ◽  
Hajime Tanaka
Keyword(s):  
Order Parameter ◽  
Structural Evolution ◽  
Characteristic Size ◽  
Number Density ◽  
Time Resolved ◽  
X Ray ◽  
Molecular Liquid ◽  
X Ray Scattering ◽  
Liquid Transition ◽  
Scattering Measurements

A liquid–liquid transition (LLT) in a single-component substance is an unconventional phase transition from one liquid to another. LLT has recently attracted considerable attention because of its fundamental importance in our understanding of the liquid state. To access the order parameter governing LLT from a microscopic viewpoint, here we follow the structural evolution during the LLT of an organic molecular liquid, triphenyl phosphite (TPP), by time-resolved small- and wide-angle X-ray scattering measurements. We find that locally favored clusters, whose characteristic size is a few nanometers, are spontaneously formed and their number density monotonically increases during LLT. This strongly suggests that the order parameter of LLT is the number density of locally favored structures and of nonconserved nature. We also show that the locally favored structures are distinct from the crystal structure and these two types of orderings compete with each other. Thus, our study not only experimentally identifies the structural order parameter governing LLT, but also may settle a long-standing debate on the nature of the transition in TPP, i.e., whether the transition is LLT or merely microcrystal formation.

Numerical Simulations Of Plasticity And Fracture In Quasicrystals

1998 ◽  
Vol 553 ◽  
Author(s):  
Hans-Rainer Trebin
Keyword(s):  
Molecular Dynamics ◽  
Crack Propagation ◽  
Numerical Simulations ◽  
Molecular Dynamics Simulations ◽  
Large Scale ◽  
Cluster Structure ◽  
Dislocation Motion ◽  
Degree Of Freedom ◽  
Characteristic Features ◽  
Dynamics Simulations

AbstractDislocation motion and crack propagation are studied in model quasicrystals both by geometrical considerations and large scale molecular dynamics simulations. It turns out that two characteristic features of quasicrystals govern plasticity and the rough appearence of cleavage planes: the phason degree of freedom and the cluster structure.

scholarly journals Rheological characteristics of steel in continuous roll casting-rolling

2021 ◽  
Vol 5 (3) ◽  
Author(s):  
O.V. Kholiavik ◽  
Alexey Nogovitsyn ◽  
Alexey Kravchuk ◽  
Alexey Samoylenko ◽  
Ruslan Boris
Keyword(s):  
Mathematical Modeling ◽  
Continuous Casting ◽  
Rheological Properties ◽  
Liquid State ◽  
Thin Sheet ◽  
Efficient Technology ◽  
Research Results ◽  
Roll Casting ◽  
Liquid States ◽  
Solid Liquid

Problems. In the process of obtaining a strip in a casting and rolling device, the question arises of combining the process of hot rolling of the solidified material and the process of crystallization of the liquid melt. This makes it possible to implement an efficient technology for producing thin-sheet products. Purpose of the study. Determination of rational parameters for performing mathematical modeling of material behavior during roll casting requires clearly defined recommendations. The material for the rolling process is steel. The starting material was used in solid, solid-liquid and liquid states. Implementation technique. The analysis of the properties of steel was carried out on the basis of the results of experiments obtained at the Physico-Technological Institute of Metals and Alloys of the National Academy of Sciences of Ukraine. To analyze the rheological properties of steel, the dependences of the yield stress for alloyed and carbon steels were used in a certain temperature range. The selected temperature range includes solidus and solid-liquid state of steel, located above 0.8 melting point. Research results. Based on the research results, the analysis of the rheological properties of steel in solid, solid-liquid and liquid states during continuous casting-rolling on rolls was carried out. The use of the obtained dependencies makes it possible to perform mathematical modeling of the deformation and hydrodynamics of the material during continuous casting-rolling of steel strips using roll casting-rolling devices. Conclusions. The constructed dependences, together with studies of the viscosity of steel in the liquid state and the resistance of steel to deformation in the solid state, most fully describe the rheological properties of steels during casting-deformation processes. The obtained dependences will make it possible to implement an ultra-efficient technology for producing thin-sheet rolled products.

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