Interface melting:  simulations of surfaces and grain boundaries at high temperatures

Broughton, Jeremy Q.; Gilmer, G. H.

doi:10.1021/j100309a009

Cited by 42 publications

(43 citation statements)

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“…For high angles, V (w) is purely repulsive for all w and reasonably well fitted by the exponential law of Eq. (1), assumed in sharpinterface theories 1,8 , at least for the largest misorientation investigated here. In contrast, for low-angle grain boundaries, V (w) is attractive for large w, but repulsive for small w, and exhibits a minimum that corresponds to the existence of a liquid layer of finite width at the melting point.…”

Section: Discussionmentioning

confidence: 83%

“…If only short-range forces are present, an exponential interaction between the interfaces is expected for large film thickness 14 . This suggests to write 1,8 V (w) = ∆γ exp − w δ ,…”

Section: A Sharp-and Diffuse-interface Theoriesmentioning

confidence: 99%

“…MD studies using LennardJones 7,8,9 and interatomic potentials for metals 10,11,12 and semiconductors such as silicon 13 have reported evidence for disordered layers at grain boundaries at different temperatures below 7,8,9,10,11,13 and above 12 the melting point. In addition, such layers have been reported to exhibit fluid-like properties in a MD study of grain-boundary shearing in a Lennard-Jones system where the shear modulus decreased sharply below the melting point 9 .…”

Section: Introductionmentioning

confidence: 99%

“…This allows us to make contact with sharp- 1,8 and diffuse-interface 1,27,28 theories of interfacial premelting. Like MD studies with truncated short-range interatomic potentials 7,8,9,10,11,12,13 , these theories neglect the effects of long-range dispersion forces considered in statistical theories of grain-boundary melting 29 and in theoretical 30 and experimental 31 studies of intergranular phases in ceramic materials. These forces are also neglected in the present phase-field crystal study that focuses on the structural component of the disjoining potential due to partial crystal ordering within premelted layers.…”

Section: Introductionmentioning

confidence: 99%

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Phase-field crystal study of grain-boundary premelting

2008

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We study the phenomenon of grain-boundary premelting for temperatures below the melting point in the phase-field crystal model of a pure material with hexagonal ordering in two dimensions. We investigate the structures of symmetric tilt boundaries as a function of misorientation θ for two different inclinations and compute in the grand canonical ensemble the "disjoining potential" V (w) that describes the fundamental interaction between crystal-melt interfaces as a function of the premelted layer width w, which is defined here in terms of the excess mass of the grain boundary via a Gibbs construction. The results reveal qualitatively different behaviors for high-angle grain boundaries that are uniformly wetted, with w diverging logarithmically as the melting point is approached from below, and low-angle boundaries that are punctuated by liquid pools surrounding dislocations, separated by solid bridges. The latter persist over a superheated range of temperature. This qualitative difference between high-and low-angle boundaries is reflected in the w-dependence of the disjoining potential that is purely repulsive (V ′ (w) < 0 for all w) for misorientations larger than a critical angle θc, but switches from repulsive at small w to attractive at large w for θ < θc. In the latter case, V (w) has a minimum that corresponds to a premelted boundary of finite width at the melting point. Furthermore, we find that the standard wetting condition γ gb (θc) = 2γ sl gives a much too low estimate of θc when a low-temperature value of the grain boundary energy γ gb is used. In contrast, a reasonable lower-bound estimate can be obtained if γ gb is extrapolated to the melting point, taking into account both the elastic softening of the material at high homologous temperature and local melting around dislocations.

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Section: Discussionmentioning

confidence: 83%

“…If only short-range forces are present, an exponential interaction between the interfaces is expected for large film thickness 14 . This suggests to write 1,8 V (w) = ∆γ exp − w δ ,…”

Section: A Sharp-and Diffuse-interface Theoriesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Phase-field crystal study of grain-boundary premelting

2008

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“…The general mechanism was proposed long ago, on the basis of qualitative arguments ͑Tammann, 1909; Stranski, 1942;Frenkel, 1946͒, but the principles of the modern theory were explicitly stated only many years later ͑Kristensen and Cotterill, 1977; Kuroda and Lacmann, 1982;Broughton and Gilmer, 1983a, 1983b, 1983c, 1984a, 1984bLipowsky and Speth, 1983;Furukawa et al, 1987;Nenow and Trayanov, 1989͒. Premelting is the general term for the phenomenon which can occur at three different classes of interface: surface melting between a solid and its vapor or gaseous atmosphere, interfacial melting in contact with foreign solid or liquid, and grain-boundary melting between crystals of the same material.…”

Section: A Thermodynamics Of Premeltingmentioning

confidence: 99%

The physics of premelted ice and its geophysical consequences

2006

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The surface of ice exhibits the swath of phase-transition phenomena common to all materials and as such it acts as an ideal test bed of both theory and experiment. It is readily available, transparent, optically birefringent, and probing it in the laboratory does not require cryogenics or ultrahigh vacuum apparatus. Systematic study reveals the range of critical phenomena, equilibrium and nonequilibrium phase-transitions, and, most relevant to this review, premelting, that are traditionally studied in more simply bound solids. While this makes investigation of ice as a material appealing from the perspective of the physicist, its ubiquity and importance in the natural environment also make ice compelling to a broad range of disciplines in the Earth and planetary sciences. In this review we describe the physics of the premelting of ice and its relationship with the behavior of other materials more familiar to the condensed-matter community. A number of the many tendrils of the basic phenomena as they play out on land, in the oceans, and throughout the atmosphere and biosphere are developed.

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Interfaces and Microstructures in Materials

Hwang

2010

Ceramics Science and Technology

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Interface melting: simulations of surfaces and grain boundaries at high temperatures

Cited by 42 publications

References 0 publications

Phase-field crystal study of grain-boundary premelting

Phase-field crystal study of grain-boundary premelting

The physics of premelted ice and its geophysical consequences

Interfaces and Microstructures in Materials

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