High-Precision Nucleation Rate Measurements for Higher Melting Metals

Bokeloh, Joachim; Wilde, Gerhard

doi:10.1007/s11837-014-1027-7

Cited by 11 publications

(13 citation statements)

References 17 publications

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“…Classical Nucleation theory [10]) to describe that distribution but are not useful for experimental characterization given that multiple input parameters are unknown for the systems of current interest. It is instead more convenient to describe nucleation as a non-homogeneous Poisson process [11,[17][18][19][20][21]. A Poisson process is a purely statistical model for a series of discrete events where the average time between events is known, but the exact timing of events is random and memoryless.…”

Section: Determining the Nucleation Rate Of A Pcmmentioning

confidence: 99%

Impact of size and thermal gradient on supercooling of phase change materials for thermal energy storage

et al. 2021

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Section: Determining the Nucleation Rate Of A Pcmmentioning

confidence: 99%

Impact of size and thermal gradient on supercooling of phase change materials for thermal energy storage

et al. 2021

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“…Investigations of the interplay between homogeneous nucleation and local polymorphism [16] remain experimentally challenging to observe [11,[17][18][19][20][21][22], especially at large undercoolings ∆T = T − T M , T being the temperature of the studied liquid and T M its melting or liquidus temperature. They were often carried out using direct particle based simulation methods like molecular dynamics (MD) or Monte-Carlo (MC) [23,24].…”

Section: Introductionmentioning

confidence: 99%

Glass-forming ability of elemental zirconium

et al. 2020

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We report large-scale molecular dynamics simulations of the glass formation from the liquid phase and homogeneous nucleation phenomena of pure zirconium. For this purpose, we have built a modified embedded atom model potential, in order to reproduce relevant structural, dynamic and thermodynamic properties from ab initio and experimental data near the melting point. By means of liquid-solid interface simulations, we show that this potential provides a thermodynamic melting temperature and densities of the solid and liquid state in good agreement with experiments. Using melt-quenching simulations with one million atoms, we determine the glass transition from the temperature evolution of the inherent structure energy as well as the nose of the time-temperature-transformation curve located in the deep undercooling regime. We identify the local structural origin of the glass forming ability as a competition between bcc and five-fold polytetrahedral structures that may represent an impediment of rapid homogeneous nucleation at such high undercoolings. This suggests the ability of single elemental zirconium to form a glass from the melt with cooling rates of at least 10 12 K/s compatible with modern experiments.

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“…In specific cases that are governed by high initial purity and continuous purification through fluxing as well as by comparatively large solubility for (metallic) impurities, as in the case of most (liquid) transition metals, conditions can be obtained so that the kinetics can be described by an analysis based on homogeneous nucleation although the absence of very small impurity clusters due to the unavoidable presence of minute amounts of impurities cannot be proven. In a series of experiments on transition metals with fcc equilibrium crystal structure, quantitative nucleation rate measurements have been conducted that were based on the stochastic nature of the nucleation process [44,15,16]. Similar results and conclusions have been obtained for pure Zr that has been melted and undercooled within an electrostatic levitation facility [17].…”

Section: Nucleation Analysismentioning

confidence: 86%

“…Moreover, advances in high rate calorimetry have provided a basis for a rational explanation for the effect of melt superheat on the subsequent undercooling [7]. In spite of the uncertainties regarding the action of specific nucleants, it is possible to provide insight into undercooling mechanisms and to achieve some measure of control through a systematic analysis of the crystallization kinetics behavior in undercooled melts and amorphous phases [14][15][16][17][18][19][20]. In fact, the activity has been so extensive that within the available coverage it is not possible to discuss all aspects satisfactorily.…”

Section: Introductionmentioning

confidence: 99%

Melt undercooling and nucleation kinetics

Perepezko

Wilde

2016

Current Opinion in Solid State and Materials Science

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a b s t r a c tWhile melt undercooling is often observed during solidification the control of undercooling and nucleation is difficult due to the numerous possible heterogeneous sites present in even high purity melts. The identification of active nucleation sites has been a continuing challenge that requires developing well planned experimentation. In samples with well-defined and controlled undercooling, the identification can be established for a number of the active sites and mechanisms that can act to catalyze nucleation. The sites and mechanisms that have been identified involve primary phases developed during cooling of alloy melts, liquid-added particle interfaces being modified (e.g. by adsorption or reaction) creating a particle type independent nucleation potency, dissolved impurities precipitating out of the melt at high undercooling or acting to alter local atomic arrangements in the melt to catalyze nucleation and nucleation sites resulting from residual solid preserved in cavities in inclusions or surface coatings. Recent advances in clarifying the structure of liquids reveal local atomic arrangements such as short range order, medium range order and cluster structures, but the role of these local heterogeneities on the undercooling and crystallization behavior is incompletely understood at present.

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High-Precision Nucleation Rate Measurements for Higher Melting Metals

Cited by 11 publications

References 17 publications

Impact of size and thermal gradient on supercooling of phase change materials for thermal energy storage

Impact of size and thermal gradient on supercooling of phase change materials for thermal energy storage

Glass-forming ability of elemental zirconium

Melt undercooling and nucleation kinetics

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