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 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 Some Aspects of the Liquid Water Thermodynamic Behavior: From The Stable to the Deep Supercooled Regime

2020 ◽  
Vol 21 (19) ◽  
pp. 7269
Author(s):  
Francesco Mallamace ◽  
Giuseppe Mensitieri ◽  
Domenico Mallamace ◽  
Martina Salzano de Luna ◽  
Sow-Hsin Chen
Keyword(s):  
Liquid Water ◽  
Supercooled Liquid ◽  
Bulk Water ◽  
Bulk Liquid ◽  
Amorphous Phases ◽  
Glass Forming ◽  
Liquid Phases ◽  
Liquid Transition ◽  
Glass Forming Materials ◽  
Thermodynamic Anomalies

Liquid water is considered to be a peculiar example of glass forming materials because of the possibility of giving rise to amorphous phases with different densities and of the thermodynamic anomalies that characterize its supercooled liquid phase. In the present work, literature data on the density of bulk liquid water are analyzed in a wide temperature-pressure range, also including the glass phases. A careful data analysis, which was performed on different density isobars, made in terms of thermodynamic response functions, like the thermal expansion αP and the specific heat differences CP−CV, proves, exclusively from the experimental data, the thermodynamic consistence of the liquid-liquid transition hypothesis. The study confirms that supercooled bulk water is a mixture of two liquid “phases”, namely the high density (HDL) and the low density (LDL) liquids that characterize different regions of the water phase diagram. Furthermore, the CP−CV isobars behaviors clearly support the existence of both a liquid–liquid transition and of a liquid–liquid critical point.

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.

Crystallization Pathway in the Bulk Metallic Glass Zr41.2Ti13.8Cu12.5Ni10Be22.5

1996 ◽  
Vol 455 ◽  
Author(s):  
S. Schneider ◽  
P. Thiyagarajan ◽  
U. Geyer ◽  
W. L. Johnson
Keyword(s):  
Scattering Length ◽  
Primary Crystallization ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Amorphous Phases ◽  
New Family ◽  
Transmission Electron ◽  
Composition Fluctuations

AbstractA new family of multicomponent metallic alloys exhibits an excellent glass forming ability at moderate cooling rates of about 10K/s and a wide supercooled liquid region. These glasses are eutectic or nearly eutectic, thus far away from the compositions of competing crystalline phases. The nucleation of crystals from the homogeneous amorphous phase requires large thermally activated composition fluctuations for which the time scale is relatively long, even in the supercooled liquid. In the Zr41.2Ti13.8Cu12.5Ni10Be22.5 alloy therefore a different pathway to crystallization is observed. The initially homogeneous alloy separates into two amorphous phases. In the decomposed regions, crystallization probability increases and finally polymorphic crystallization occurs. The evolution of decomposition and succeeding primary crystallization in the bulk amorphous Zr41.2Ti13.8Cu12.5Ni10Be22.5 alloy have been studied by small angle neutron. Samples annealed isothermally in the supercooled liquid and in the solid state exhibit interference peaks indicating quasiperiodic inhomogeneities in the scattering length density. The related wavelengths increase with temperature according to the linear Cahn-Hilliard theory for spinodal decomposition. Also the time evolution of the interference peaks in the early stages is consistent with this theory. At later stages, X-ray diffraction and transmission electron microscopy investigations confirm the formation of nanocrystals in the decomposed regions.

A stochastic approach to the freezing of supercooled liquids

1983 ◽  
Vol 61 (7) ◽  
pp. 1046-1049 ◽  
Author(s):  
Amal K. Das
Keyword(s):  
Multiplicative Noise ◽  
First Passage Time ◽  
Planck Equation ◽  
Supercooled Liquid ◽  
Stochastic Approach ◽  
Passage Time ◽  
Supercooled Liquids ◽  
Mean First Passage Time ◽  
Deterministic Equation ◽  
The Mean

We have considered the freezing of a supercooled liquid, in particular water, experimentally found to be describable by the phenomenological deterministic equation dn/dt = κn(1–n), n(t) being the fraction of ice. In order to start the process of nucleation, a white noise fluctuation is invoked. This fluctuation is considered both additively and multiplicatively with respect to the deterministic equation. The mean first passage time, a quantity of direct physical interest, is calculated in both cases. With the multiplicative noise, the Itô–Stratonovich route is avoided through a suitable transformation of the Langevin equation and through the study of the resulting Fokker–Planck equation thereof.

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