Melting Mechanisms at the Limit of Superheating

Jin, Zhaohui; Gumbsch, Peter; Lu, Kun; Ma, E.

doi:10.1103/physrevlett.87.055703

Cited by 379 publications

(305 citation statements)

References 39 publications

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“…7), and the parameters that emerge from this fit are T 0 liq = 6705 K, T int = 124 K. We can now check that this value of T int obtained by empirical fitting is indeed consistent with the prediction of eqn (6). From our EAM simulations of the liquid, we obtain the estimate C v,liq /k B = 3.36.…”

Section: Discussionsupporting

confidence: 72%

The kinetics of homogeneous melting beyond the limit of superheating

Alfè

Cazorla

Gillan

2011

The Journal of Chemical Physics

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Molecular dynamics simulation is used to study the time-scales involved in the homogeneous melting of a superheated crystal. The interaction model used is an embedded-atom model for Fe developed in previous work, and the melting process is simulated in the microcanonical (N, V, E) ensemble. We study periodically repeated systems containing from 96 to 7776 atoms, and the initial system is always the perfect crystal without free surfaces or other defects. For each chosen total energy E and number of atoms N , we perform several hundred statistically independent simulations, with each simulation lasting for between 500 ps and 10 ns, in order to gather statistics for the waiting time τ w before melting occurs. We find that the probability distribution of τ w is roughly exponential, and that the mean value τ w depends strongly on the excess of the initial steady temperature of the crystal above the superheating limit identified by other researchers. The mean τ w also depends strongly on system size in a way that we have quantified. For very small systems of ∼ 100 atoms, we observe a persistent alternation between the solid and liquid states, and we explain why this happens. Our results allow us to draw conclusions about the reliability of the recently proposed Z method for determining the melting properties of simulated materials, and to suggest ways of correcting for the errors of the method.

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Section: Discussionsupporting

confidence: 72%

The kinetics of homogeneous melting beyond the limit of superheating

Alfè

Cazorla

Gillan

2011

The Journal of Chemical Physics

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“…Usually Born's conjecture is interpreted as suggesting continuous vanishment. This is an interesting and much debated question in the case of superheated crystals [38][39][40][41] approaching their metastability limit at T s [82]. The same question is relevant also for supercooled liquids and glasses since, as emphasized in a recent work [42], the dynamical transition at T d (or the MCT critical temperature T c ) can be regarded as an analogue of the spinodal behaviour of superheated crystals at T s .…”

Section: Rigidity Of Metabasinmentioning

confidence: 97%

“…It has been proposed a long time ago by Born [37] that melting of solids may be signaled by vanishing of the rigidity. Although this rigidity crisis scenario obviously does not apply to the equilibrium liquid-solid transitions which are 1st order phase transitions, whether it is relevant for the melting of superheated metastable crystals approaching the spinodal temperature T s from below is an intriguing question [38][39][40][41]. Interestingly enough, there is an intimate analogy [42] between the melting of metastable amorphous solids at the dynamical transition temperature T d (or the MCT critical temperature T c ) and the melting of superheated metastable crystals at T s .…”

Section: Introductionmentioning

confidence: 99%

Replica theory of the rigidity of structural glasses

Yoshino

2012

The Journal of Chemical Physics

108

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We present a first principle scheme to compute the rigidity, i. e. the shear-modulus of structural glasses at finite temperatures using the cloned liquid theory, which combines the replica theory and the liquid theory. With the aid of the replica method which enables disentanglement of thermal fluctuations in liquids into intra-state and inter-state fluctuations, we extract the rigidity of metastable amorphous solid states in the supercooled liquid and glass phases. The result can be understood intuitively without replicas. As a test case, we apply the scheme to the supercooled and glassy state of a binary mixture of soft-spheres. The result compares well with the shear-modulus obtained by a previous molecular dynamic simulation. The rigidity of metastable states is significantly reduced with respect to the instantaneous rigidity, namely the Born term, due to non-affine responses caused by displacements of particles inside cages at all temperatures down to T = 0. It becomes nearly independent of temperature below the Kauzmann temperature TK. At higher temperatures in the supercooled liquid state, the non-affine correction to the rigidity becomes stronger suggesting melting of the metastable solid state. Inter-state part of the static response implies jerky, intermittent stress-strain curves with static analogue of yielding at mesoscopic scales.

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“…The fraction of defects in ice is 1.5% at 150 K, and decreases to 0.7% at 100 K. As the temperature goes up from 150 K to 360 K, the fraction of defects increases continuously and exceeds 60%, and the fivefold symmetry of a pentagonal ice nanotube disappears gradually. In contrast, when a bulk solid is heated, a small number of defects immediately lead to a collapse of the entire crystalline structure at a specific temperature (27)(28)(29). Given the fact that simulated water and simple liquids may be continuously transformed to ordered solids in quasi-1D (1, 4) and quasi-2D nanopores (3, 6) while such gradual transformation is not observed for the bulk systems, we suspect that a decisive factor enabling water and other simple molecules to exhibit continuous freezing is confinement.…”

Section: Significancementioning

confidence: 99%

Solid−liquid critical behavior of water in nanopores

Mochizuki

Koga

2015

Proc. Natl. Acad. Sci. U.S.A.

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Nanoconfined liquid water can transform into low-dimensional ices whose crystalline structures are dissimilar to any bulk ices and whose melting point may significantly rise with reducing the pore size, as revealed by computer simulation and confirmed by experiment. One of the intriguing, and as yet unresolved, questions concerns the observation that the liquid water may transform into a low-dimensional ice either via a first-order phase change or without any discontinuity in thermodynamic and dynamic properties, which suggests the existence of solid−liquid critical points in this class of nanoconfined systems. Here we explore the phase behavior of a model of water in carbon nanotubes in the temperature−pressure− diameter space by molecular dynamics simulation and provide unambiguous evidence to support solid−liquid critical phenomena of nanoconfined water. Solid−liquid first-order phase boundaries are determined by tracing spontaneous phase separation at various temperatures. All of the boundaries eventually cease to exist at the critical points and there appear loci of response function maxima, or the Widom lines, extending to the supercritical region. The finite-size scaling analysis of the density distribution supports the presence of both first-order and continuous phase changes between solid and liquid. At around the Widom line, there are microscopic domains of two phases, and continuous solid−liquid phase changes occur in such a way that the domains of one phase grow and those of the other evanesce as the thermodynamic state departs from the Widom line.T he possibility of the solid-liquid critical point has been reported by computer simulation studies of various systems in quasi-one, quasi-two, and three dimensions that exhibit both continuous and discontinuous changes in thermodynamic functions and other order parameters (1-7). However, the idea that a solid-liquid phase boundary never terminates at the critical point is still commonly accepted as a law of nature, largely because of the famous symmetry argument (8, 9) together with the lack of experimental observations. Furthermore, critical phenomena in quasi-1D systems are often considered impossible from a different point of view; that is, to begin with, there is no first-order phase transition in 1D systems as proved for solvable models (10) or shown by the phenomenological argument (9). Therefore, a thorough investigation is much needed to support or reject the possibility of the solid-liquid critical point. We examine the phase behavior of a model system of water confined in a quasi-1D nanopore (1,(11)(12)(13)(14)(15) and provide evidence to support the existence of first-order phase transitions and solid-liquid critical points. Results and DiscussionsFirst, we explore possible solid-liquid critical points of the confined water by calculating isotherms in the "pressure-volume" plane, where the pressure is actually P zz , a component of pressure tensor along the tube axis, or simply the axial pressure, and the volume is ℓ z , the length of simulatio...

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Melting Mechanisms at the Limit of Superheating

Cited by 379 publications

References 39 publications

The kinetics of homogeneous melting beyond the limit of superheating

The kinetics of homogeneous melting beyond the limit of superheating

Replica theory of the rigidity of structural glasses

Solid−liquid critical behavior of water in nanopores

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