scholarly journals Orientation dependence of heterogeneous nucleation at the Cu–Pb solid-liquid interface

2016 ◽  
Vol 145 (21) ◽  
pp. 211914 ◽  
Author(s):  
J. Pablo Palafox-Hernandez ◽  
Brian B. Laird
Keyword(s):  
Heterogeneous Nucleation ◽  
Orientation Dependence ◽  
Liquid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid

THE EFFECT OF GROWTH CONDITIONS UPON THE SOLIDIFICATION OF A BINARY ALLOY

1956 ◽  
Vol 34 (1) ◽  
pp. 96-121 ◽  
Author(s):  
W. A. Tiller ◽  
J. W. Rutter
Keyword(s):  
Binary Alloy ◽  
Impurity Content ◽  
Growth Conditions ◽  
Orientation Dependence ◽  
Liquid Interface ◽  
Critical Ratio ◽  
Liquid Lead ◽  
Careful Study ◽  
Solid Liquid Interface ◽  
Solid Liquid

This investigation provides both a theoretical and an experimental analysis of the factors which affect the mode of solidification of a binary alloy. These factors are: (i) the concentration of solute in the melt (C0); (ii) the rate of solidification (R); (iii) the temperature gradient in the melt at the solid–liquid interface (G). Extremely high purity lead was produced by zone refining and, from this material, crystals containing known concentrations of tin, silver, and gold were grown under a range of well-controlled growth conditions. The mode of solidification was investigated by a careful study of the change in appearance of the solid–liquid interface with a change in growth conditions. For a crystal containing a specific C0 of solute it was observed that (a) the transition from a smooth interface to a cellular interface occurred at a critical ratio of G to R; (b) the width of the cells varied inversely as G and inversely as R; (c) the transition from a cellular interface to a dendritic interface exhibited a large orientation dependence, and for a constant orientation breakdown occurred at a critical ratio of G to [Formula: see text]. The experimental observations confirm both the existence of a solute-rich layer of liquid adjacent to the solid-liquid interface and its quantitative features. From this agreement with theory the diffusion coefficients of tin, silver, and gold in liquid lead at 327 °C. are determined. This work serves to illustrate the effect of extremely small amounts of particular solutes upon the development of substructures during solidification. A technique is proposed for obtaining a measure of the purity of low impurity content alloys.

scholarly journals Nanoscale Mapping of Non-Uniform Heterogeneous Nucleation Kinetics Mediated by Surface Chemistry

2019 ◽  
Author(s):  
Mei Wang ◽  
Thilini Umesha Dissanayake ◽  
Chiwoo Park ◽  
Karen J. Gaskell ◽  
Taylor Woehl
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Surface Chemistry ◽  
Heterogeneous Nucleation ◽  
Liquid Interface ◽  
Nucleation Kinetics ◽  
Nucleation Sites ◽  
Solid Liquid Interface ◽  
Solid Liquid

<p>Nucleation underlies the formation of many liquid-phase synthetic and natural materials with applications in materials chemistry, geochemistry, biophysics, and structural biology. Most liquid-phase nucleation processes are heterogeneous, occurring at specific nucleation sites at a solid-liquid interface; however, the chemical and topographical identity of these nucleation sites and how nucleation kinetics vary from site-to-site remains mysterious. Here we utilize <i>in situ</i> liquid cell electron microscopy to unveil counterintuitive nanoscale non-uniformities in heterogeneous nucleation kinetics on a macroscopically uniform solid-liquid interface. Time-resolved <i>in situ</i> electron microscopy imaging of silver nanoparticle nucleation at a water-silicon nitride interface showed apparently randomly-located nucleation events at the interface. However, nanometric maps of local nucleation kinetics uncovered nanoscale interfacial domains with either slow or rapid nucleation. Interestingly, the interfacial domains vanished at high supersaturation ratio, giving way to rapid spatially uniform nucleation kinetics. Atomic force microscopy and nanoparticle labeling experiments revealed a topographically flat, chemically heterogeneous interface with nanoscale interfacial domains of functional groups similar in size to those observed in the nanometric nucleation maps. These results, along with a semi-quantitative nucleation model, indicate that a chemically non-uniform interface presenting different free energy barriers to heterogeneous nucleation underlies our observations of non-uniform nucleation kinetics. Overall, our results introduce a new imaging modality, nanometric nucleation mapping, and provide important new insights into the impact of surface chemistry on microscopic spatial variations in heterogeneous nucleation kinetics that have not been previously observed.</p>

Nanoscale Mapping of Non-Uniform Heterogeneous Nucleation Kinetics Mediated by Surface Chemistry

2019 ◽  
Author(s):  
Mei Wang ◽  
Thilini Umesha Dissanayake ◽  
Chiwoo Park ◽  
Karen J. Gaskell ◽  
Taylor Woehl
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Surface Chemistry ◽  
Heterogeneous Nucleation ◽  
Liquid Interface ◽  
Nucleation Kinetics ◽  
Nucleation Sites ◽  
Solid Liquid Interface ◽  
Solid Liquid

<p>Nucleation underlies the formation of many liquid-phase synthetic and natural materials with applications in materials chemistry, geochemistry, biophysics, and structural biology. Most liquid-phase nucleation processes are heterogeneous, occurring at specific nucleation sites at a solid-liquid interface; however, the chemical and topographical identity of these nucleation sites and how nucleation kinetics vary from site-to-site remains mysterious. Here we utilize <i>in situ</i> liquid cell electron microscopy to unveil counterintuitive nanoscale non-uniformities in heterogeneous nucleation kinetics on a macroscopically uniform solid-liquid interface. Time-resolved <i>in situ</i> electron microscopy imaging of silver nanoparticle nucleation at a water-silicon nitride interface showed apparently randomly-located nucleation events at the interface. However, nanometric maps of local nucleation kinetics uncovered nanoscale interfacial domains with either slow or rapid nucleation. Interestingly, the interfacial domains vanished at high supersaturation ratio, giving way to rapid spatially uniform nucleation kinetics. Atomic force microscopy and nanoparticle labeling experiments revealed a topographically flat, chemically heterogeneous interface with nanoscale interfacial domains of functional groups similar in size to those observed in the nanometric nucleation maps. These results, along with a semi-quantitative nucleation model, indicate that a chemically non-uniform interface presenting different free energy barriers to heterogeneous nucleation underlies our observations of non-uniform nucleation kinetics. Overall, our results introduce a new imaging modality, nanometric nucleation mapping, and provide important new insights into the impact of surface chemistry on microscopic spatial variations in heterogeneous nucleation kinetics that have not been previously observed.</p>

Observation of Femtosecond Acoustic Anomaly in a Solid Liquid Interface

2020 ◽  
Vol 124 (5) ◽  
pp. 2987-2993
Author(s):  
Chi-Kuang Sun ◽  
Yi-Ting Yao ◽  
Chih-Chiang Shen ◽  
Mu-Han Ho ◽  
Tien-Chang Lu ◽  
...  
Keyword(s):  
Liquid Interface ◽  
Acoustic Anomaly ◽  
Solid Liquid Interface ◽  
Solid Liquid
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