Amorphous Nucleation Precursor in Highly Nonequilibrium Fluids

Tóth, Gyula I.; Pusztai, Tamás; Tegze, György; Tóth, Gergely; Gránásy, László

doi:10.1103/physrevlett.107.175702

Cited by 85 publications

(121 citation statements)

References 35 publications

Supporting

Mentioning

109

Contrasting

Order By: Relevance

“…However, in addition to these the nucleation process itself may play an important role, as discussed in Refs. [83][84][85][86]. These studies show that the critical nucleus is likewise a structure that may be incommensurate with the equilibrium crystal lattice structure so the nucleation process can itself generate disorder in the system.…”

Section: Discussionmentioning

confidence: 99%

Solidification in soft-core fluids: Disordered solids from fast solidification fronts

et al. 2014

View full text Add to dashboard Cite

Using dynamical density functional theory we calculate the speed of solidification fronts advancing into a quenched two-dimensional model fluid of soft-core particles. We find that solidification fronts can advance via two different mechanisms, depending on the depth of the quench. For shallow quenches, the front propagation is via a nonlinear mechanism. For deep quenches, front propagation is governed by a linear mechanism and in this regime we are able to determine the front speed via a marginal stability analysis. We find that the density modulations generated behind the advancing front have a characteristic scale that differs from the wavelength of the density modulation in thermodynamic equilibrium, i.e., the spacing between the crystal planes in an equilibrium crystal. This leads to the subsequent development of disorder in the solids that are formed. For the onecomponent fluid, the particles are able to rearrange to form a well-ordered crystal, with few defects. However, solidification fronts in a binary mixture exhibiting crystalline phases with square and hexagonal ordering generate solids that are unable to rearrange after the passage of the solidification front and a significant amount of disorder remains in the system.

show abstract

Section: Discussionmentioning

confidence: 99%

Solidification in soft-core fluids: Disordered solids from fast solidification fronts

et al. 2014

View full text Add to dashboard Cite

show abstract

“…For the case of a Yukawa fluid (bcc), interfacial tension are too large by a factor of 2 and anisotropies are greatly exaggerated [12]. An attempt to relate the PFC pair correlations in an amorphous solid (bcc part of the PFC phase diagram) to a pair potential yielded a strongly oscillatory potential with a rather soft core [22]. This potential is very much unlike the Yukawa potential or a possible potential for iron.…”

Section: Phase Field Crystal (Pfc) Modelmentioning

confidence: 99%

Solid phase properties and crystallization in simple model systems

Turci

Schilling

Yamani

et al. 2014

Eur. Phys. J. Spec. Top.

View full text Add to dashboard Cite

Abstract. We review theoretical and simulational approaches to the description of equilibrium bulk crystal and interface properties as well as to the nonequilibrium processes of homogeneous and heterogeneous crystal nucleation for the simple model systems of hard spheres and Lennard-Jones particles. For the equilibrium properties of bulk and interfaces, density functional theories employing fundamental measure functionals prove to be a precise and versatile tool, as exemplified with a closer analysis of the hard sphere crystal-liquid interface. A detailed understanding of the dynamic process of nucleation in these model systems nevertheless still relies on simulational approaches. We review bulk nucleation and nucleation at structured walls and examine in closer detail the influence of walls with variable strength on nucleation in the Lennard-Jones fluid. We find that a planar crystalline substrate induces the growth of a crystalline film for a large range of lattice spacings and interaction potentials. Only a strongly incommensurate substrate and a very weakly attractive substrate potential lead to crystal growth with a non-zero contact angle.

show abstract

“…Previous studies of Langevin noise in PFC have used such a cutoff to carry out simulations [74][75][76][77] . The issue of whether introducing noise may lead to a double counting of fluctuations has often been discussed.…”

Section: B Short-wavelength Noise Cutoffmentioning

confidence: 99%

Phase-field-crystal study of grain boundary premelting and shearing in bcc iron

et al. 2013

View full text Add to dashboard Cite

We use the phase-field-crystal (PFC) method to investigate the equilibrium premelting and nonequilibrium shearing behaviors of [001] symmetric tilt grain boundaries (GBs) at high homologous temperature over the complete range of misorientation 0 < θ < 90 • in classical models of bcc Fe. We characterize the dependence of the premelted layer width W as a function of temperature and misorientation. In addition, we compute the thermodynamic disjoining potential whose derivative with respect to W represents the structural force between crystal-melt interfaces due to the spatial overlap of density waves. The disjoining potential is also computed by molecular dynamics (MD) simulations, for quantitative comparison with PFC simulations, and coarse-grained amplitude equations (AE) derived from PFC that provide additional analytical insights. We find that, for GBs over an intermediate range of misorientation (θmin < θ < θmax), W diverges as the melting temperature is approached from below, corresponding to a purely repulsive disjoining potential, while for GBs outside this range (θ < θmin or θmax < θ < 90 • ), W remains finite at the melting point. In the latter case, W corresponds to a shallow attractive minimum of the disjoining potential. The misorientation range where W diverges predicted by PFC simulations is much smaller than the range predicted by MD simulations when the small dimensionless parameter ǫ of the PFC model is matched to liquid structure factor properties. However it agrees well with MD simulations with a lower ǫ value chosen to match the ratio of bulk modulus and solid-liquid interfacial free-energy, consistent with the amplitude-equation prediction that θmin and 90 • − θmax scale as ∼ ǫ 1/2 . The incorporation of thermal fluctuations in PFC is found to have a negligible effect on this range. In response to a shear stress parallel to the GB plane, GBs in PFC simulations exhibit coupled motion normal to this plane or sliding. Furthermore, the coupling factor exhibits a discontinuous change as a function of θ that reflects a transition between two coupling modes. Sliding is only observed over a range of misorientation that is a strongly increasing function of temperature for T /TM ≥ 0.8 and matches roughly the range where W diverges at the melting point. The coupling factor for the two coupling modes is in excellent quantitative agreement with previous theoretical predictions [J. W. Cahn, Y. Mishin, and A. Suzuki, Acta Mater. 54, 4953 (2006)].

show abstract

Amorphous Nucleation Precursor in Highly Nonequilibrium Fluids

Cited by 85 publications

References 35 publications

Solidification in soft-core fluids: Disordered solids from fast solidification fronts

Solidification in soft-core fluids: Disordered solids from fast solidification fronts

Solid phase properties and crystallization in simple model systems

Phase-field-crystal study of grain boundary premelting and shearing in bcc iron

Contact Info

Product

Resources

About