Kinetics of isothermal nucleation in a supercooled iron melt

Evteev, Alexander V.; Косилов, А. Т.; Levchenko, Elena V.; Logachev, O. B.

doi:10.1134/s1063783406050015

Cited by 29 publications

(28 citation statements)

References 15 publications

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“…Fractal percolated clusters were later observed by Evteev et al and later included in a review by Ojovan [18][19][20]. In molecular dynamic simulations of pure, supercooled iron, Evteev et al reported that the structural organization of the amorphous phase is believed to be a result of the formation and subsequent growth of mutually penetrating icosahedrons that contain atoms at the vertices and at the centers [18,19].…”

Section: Twinkling Fractal Theorymentioning

confidence: 95%

“…Medvedev et al first observed the argument that glass formation is caused by the formation of solid-like percolation clusters made of high-density configurations in molecular dynamics simulations of liquid, supercooled, and quenched states of rubidium that utilized the Voronoi-Delanuay method [17]. Fractal percolated clusters were later observed by Evteev et al and later included in a review by Ojovan [18][19][20]. In molecular dynamic simulations of pure, supercooled iron, Evteev et al reported that the structural organization of the amorphous phase is believed to be a result of the formation and subsequent growth of mutually penetrating icosahedrons that contain atoms at the vertices and at the centers [18,19].…”

Section: Twinkling Fractal Theorymentioning

confidence: 97%

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Observing the twinkling fractal nature of the glass transition

Stanzione

Strawhecker

Wool

2011

Journal of Non-Crystalline Solids

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Section: Twinkling Fractal Theorymentioning

confidence: 95%

Section: Twinkling Fractal Theorymentioning

confidence: 97%

Observing the twinkling fractal nature of the glass transition

Stanzione

Strawhecker

Wool

2011

Journal of Non-Crystalline Solids

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“…4. Light field TEM image of interstitial glass strongly saturated by nanometric sized gaseous bubbles in spherule NZ8 bn4 25.9. volume provide evidence for a different regime of solidification and is consistent with specific features of isothermal homogeneous crystallization of the over cooled melt [8]. Such crystallization may proceed at the expense of latent heat of crystallization during solidification, when radiation is the only way of heat removal in the absence of thermal conductivity [9].…”

Section: Geochemistrymentioning

confidence: 59%

New data on the microstructure of silicate Cosmic spherules

2012

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The flux of cosmic matter on the Earth is ~40 000 ± 20 000 t per year. A main fraction of the flux is present by micrometeorites that are particles <1-2 mm in size. Cosmic spherules (CSs), scoriaceous, and unmelted micrometeorites are main micrometeorite types. According to the generally accepted aerodynamic model [2][3][4], CSs are formed from micrometeoroids, which were melted during high speed entry in the Earth' atmosphere.Transmission electron microscopy (TEM) study of silicate CSs with a cryptocrystalline texture collected in the area of the Tunguska event (Tunguska collection [5]) and extracted from glacier deposits of Novaya Zemlya (Novaya Zemlya collection [6]) allowed us to obtain new data on the microtextural patterns of spherules of this type. T3 2 spherule (Tungus collec tion) with a size of 130 × 200 µm (Fig. 1) has the fol lowing bulk chemical composition (wt %): SiO 2 48.9; TiO 2 0.08; Al 2 O 3 2.17; Cr 2 O 3 0.56; FeO 16.0; MnO 0.30; NiO 0.04; MgO 30.4; CaO 1.63; P 2 O 5 0.05 [5].TEM data show that the microtexture of the T3 2 spherule is characterized by olivine (Fo 76-79 ) crystals of the same sizes (~500 × 1000 nm) regularly distrib uted in glass of the following average bulk composition (wt %): SiO 2 67; FeO 7; MgO 3; CaO 5; Al 2 O 3 18 (Fig. 2). Crystals similarly oriented in silicate glass have elongation in the [100] direction and form paral lel chains along this direction demonstrating a texture of the "stone packing" type. Ends of the crystals have a round shape. Crystal faces are strongly decorated by gaseous inclusions demonstrating the effect of corroded faces (Fig. 2). The gaseous bubbles are ~30 nm in diameter. The microtexture of the sample from the Novaya Zemlya collection is amazingly similar to the microtexture of "stone packing" type observed in the T3 2 spherule from the Tunguska collection.The NZ8 bn4 25.9 spherule with a size of 100 × 70 µm is also composed of spatially ordered euhedral olivine (Fo 77 ) crystals with a size of 1-3 × 0.7-1 µm in a glass matrix (Fig. 3) saturated with gaseous bubbles (Fig. 4). The size of gaseous bubbles is 20-50 nm. The composition of glass is the following (wt %): SiO 2 61; Al 2 O 3 19-21; FeO 8-9; MgO 4-5; CaO 6. There are no clear microtextural differences between the central and peripheral parts of the T3 2 and NZ8 bn4 25.9 spherules. The modal abundance of the olivine crystals in glass is ~74%.The microtexture of the "stone packing" type have been not described anywhere, as it is known for the authors and it is observed for the first time; the texture differs from the "macroscopic" barred texture typical of silicate CSs and olivine chondrules in meteorites. In contrast to the barred "macrotexture," "stone pack 100 µm Fig. 1. Back scattered electron image of silicate cosmic spherule T3 2 (Tunguska collection). The cryptocrystal line silicate matrix (gray) contains a droplike metallic inclusion (white).GEOCHEMISTRY

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“…4 show that the main structure changes in the non-crystalline phase take place in the temperature interval from 450 to 700 K, and maximum of the specific heat of non-crystalline phase responds to temperature T ffi550 K. As it was found in the result of simulation in Ref. [32], icosahedral clusters with long lifetime in amorphous Fe hinder the formation of crystallization centers. Our data for Al are an evidence of comparatively long life of big clusters at the temperatures below 550 K. The averaged lifetimes of the icosahedral surrounding of separate atoms are roughly the same as the above-mentioned lifetimes of big clusters.…”

Section: Dt/t After Simplifications Of Their Resultsmentioning

confidence: 77%