Experimental studies of crystal nucleation: metals and colloids

Abstract

Crystallization is one of the most important phase transformations of first order. In the case of metals and alloys, the liquid phase is the parent phase of materials production. The conditions of the crystallization process control the as-solidified material in its chemical and physical properties. Nucleation initiates the crystallization of a liquid. It selects the crystallographic phase, stable or meta-stable. Its detailed knowledge is therefore mandatory for the design of materials. We present techniques of containerless processing for nucleation studies of metals and alloys. Experimental results demonstrate the power of these methods not only for crystal nucleation of stable solids but in particular also for investigations of crystal nucleation of metastable solids at extreme undercooling. This concerns the physical nature of heterogeneous versus homogeneous nucleation and nucleation of phases nucleated under non-equilibrium conditions. The results are analyzed within classical nucleation theory that defines the activation energy of homogeneous nucleation in terms of the interfacial energy and the difference of Gibbs free energies of solid and liquid. The interfacial energy acts as barrier for the nucleation process. Its experimental determination is difficult in the case of metals. In the second part of this work we therefore explore the potential of colloidal suspensions as model systems for the crystallization process. The nucleation process of colloids is observed in situ by optical observation and ultra-small angle X-ray diffraction using high intensity synchrotron radiation. It allows an unambiguous discrimination of homogeneous and heterogeneous nucleation as well as the determination of the interfacial free energy of the solid-liquid interface. Our results are used to construct Turnbull plots of colloids, which are discussed in relation to Turnbull plots of metals and support the hypothesis that colloids are useful model systems to investigate crystal nucleation.

Autoren

Dieter M Herlach
Thomas Palberg
Ina Klassen
Stefan Klein
Raphael Kobold

DOI

10.1063/1.4963684

eISSN

1089-7690

ISSN

0021-9606

Ausgabe der Veröffentlichung

21

Zeitschrift

The Journal of Chemical Physics

Sprache

en

Online publication date

2016

Datum der Veröffentlichung

2016

Status

Published

Herausgeber

AIP Publishing

Herausgeber URL

http://dx.doi.org/10.1063/1.4963684

Datum der Datenerfassung

2023

Titel

Overview: Experimental studies of crystal nucleation: Metals and colloids

Ausgabe der Zeitschrift

145

Datenquelle: Crossref

Abstract

Crystallization is one of the most important phase transformations of first order. In the case of metals and alloys, the liquid phase is the parent phase of materials production. The conditions of the crystallization process control the as-solidified material in its chemical and physical properties. Nucleation initiates the crystallization of a liquid. It selects the crystallographic phase, stable or meta-stable. Its detailed knowledge is therefore mandatory for the design of materials. We present techniques of containerless processing for nucleation studies of metals and alloys. Experimental results demonstrate the power of these methods not only for crystal nucleation of stable solids but in particular also for investigations of crystal nucleation of metastable solids at extreme undercooling. This concerns the physical nature of heterogeneous versus homogeneous nucleation and nucleation of phases nucleated under non-equilibrium conditions. The results are analyzed within classical nucleation theory that defines the activation energy of homogeneous nucleation in terms of the interfacial energy and the difference of Gibbs free energies of solid and liquid. The interfacial energy acts as barrier for the nucleation process. Its experimental determination is difficult in the case of metals. In the second part of this work we therefore explore the potential of colloidal suspensions as model systems for the crystallization process. The nucleation process of colloids is observed in situ by optical observation and ultra-small angle X-ray diffraction using high intensity synchrotron radiation. It allows an unambiguous discrimination of homogeneous and heterogeneous nucleation as well as the determination of the interfacial free energy of the solid-liquid interface. Our results are used to construct Turnbull plots of colloids, which are discussed in relation to Turnbull plots of metals and support the hypothesis that colloids are useful model systems to investigate crystal nucleation.

Addresses

Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln, Germany.

Autoren

Dieter M Herlach
Thomas Palberg
Ina Klassen
Stefan Klein
Raphael Kobold

DOI

10.1063/1.4963684

eISSN

1089-7690

Externe Identifier

PubMed Identifier: 28799394

Funding acknowledgements

Deutsche Forschungsgemeinschaft: HE1601/24
Deutsche Forschungsgemeinschaft: Pa459/16
European Space Agency: 15236/02/NL/SH
Deutsche Forschungsgemeinschaft: HE1601/21
Deutsche Forschungsgemeinschaft: Pa459/17
German Aerospace Center Space Management: 50WM1140

Open access

false

ISSN

0021-9606

Ausgabe der Veröffentlichung

21

Zeitschrift

The Journal of chemical physics

Sprache

eng

Medium

Print

Paginierung

211703

Datum der Veröffentlichung

2016

Status

Published

Datum der Datenerfassung

2017

Titel

Overview: Experimental studies of crystal nucleation: Metals and colloids.

Sub types

Journal Article

Ausgabe der Zeitschrift

145

Datenquelle: Europe PubMed Central

Abstract

Crystallization is one of the most important phase transformations of first order. In the case of metals and alloys, the liquid phase is the parent phase of materials production. The conditions of the crystallization process control the as-solidified material in its chemical and physical properties. Nucleation initiates the crystallization of a liquid. It selects the crystallographic phase, stable or meta-stable. Its detailed knowledge is therefore mandatory for the design of materials. We present techniques of containerless processing for nucleation studies of metals and alloys. Experimental results demonstrate the power of these methods not only for crystal nucleation of stable solids but in particular also for investigations of crystal nucleation of metastable solids at extreme undercooling. This concerns the physical nature of heterogeneous versus homogeneous nucleation and nucleation of phases nucleated under non-equilibrium conditions. The results are analyzed within classical nucleation theory that defines the activation energy of homogeneous nucleation in terms of the interfacial energy and the difference of Gibbs free energies of solid and liquid. The interfacial energy acts as barrier for the nucleation process. Its experimental determination is difficult in the case of metals. In the second part of this work we therefore explore the potential of colloidal suspensions as model systems for the crystallization process. The nucleation process of colloids is observed in situ by optical observation and ultra-small angle X-ray diffraction using high intensity synchrotron radiation. It allows an unambiguous discrimination of homogeneous and heterogeneous nucleation as well as the determination of the interfacial free energy of the solid-liquid interface. Our results are used to construct Turnbull plots of colloids, which are discussed in relation to Turnbull plots of metals and support the hypothesis that colloids are useful model systems to investigate crystal nucleation.

Autoren

Dieter M Herlach
Thomas Palberg
Ina Klassen
Stefan Klein
Raphael Kobold

Autoren-URL

https://www.ncbi.nlm.nih.gov/pubmed/28799394

DOI

10.1063/1.4963684

eISSN

1089-7690

Ausgabe der Veröffentlichung

21

Zeitschrift

J Chem Phys

Sprache

eng

Country

United States

Paginierung

211703

Datum der Veröffentlichung

2016

Status

Published

Datum, an dem der Datensatz öffentlich gemacht wurde

2018

Titel

Overview: Experimental studies of crystal nucleation: Metals and colloids.

Sub types

Journal Article

Ausgabe der Zeitschrift

145

Datenquelle: PubMed

Abstract

Crystallization is one of the most important phase transformations of first order. In the case of metals and alloys, the liquid phase is the parent phase of materials production. The conditions of the crystallization process control the as-solidified material in its chemical and physical properties. Nucleation initiates the crystallization of a liquid. It selects the crystallographic phase, stable or meta-stable. Its detailed knowledge is therefore mandatory for the design of materials. We present techniques of containerless processing for nucleation studies of metals and alloys. We demonstrate the power of these methods for crystal nucleation of stable solids but in particular also for investigations of crystal nucleation of metastable solids at extreme undercooling. This concerns the issue of heterogeneous versus homogeneous nucleation and non-equilibrium conditions. The results are analyzed within classical nucleation theory, where the activation energy of homogeneous nucleation depends on the interfacial energy and the difference of Gibbs free energies of solid and liquid. The interfacial energy acts as barrier for the nucleation process. Its experimental determination is difficult in the case of metals. In the second part of this work we therefore explore the use of colloidal suspensions as models for the crystallization process. Their nucleation process is observed in situ by optical techniques and ultra-small angle X-ray diffraction using high intensity synchrotron radiation. It allows an unambiguous discrimination of homogeneous and heterogeneous nucleation as well as the determination of the interfacial free energy of the solid-liquid interface. Our results are used to construct Turnbull plots of colloids, which are discussed in relation to Turnbull plots of metals and support the hypothesis that colloids are useful model systems to investigate crystal nucleation.

Autoren

Diter M Herlach
Thomas Palberg

Autoren-URL

http://arxiv.org/abs/1605.03511v2

Schlüsselwörter

cond-mat.mtrl-sci
cond-mat.mtrl-sci

Notes

Invited review submitted for a special issue of J. Chem. Phys. "Overview Articles - Special Topic: Nucleation: New Concepts and Discoveries on the physics of nucleation". Submitted 2016 May 10. 61 pages 189 References 25 Figures. Abstract above is slightly shoretened to match ArXive rules v2 - added reprint permissions to all figures

Datum der Veröffentlichung

2016

Herausgeber URL

http://dx.doi.org/10.1063/1.4963684

Datum der Datenerfassung

2016

Datum, an dem der Datensatz öffentlich gemacht wurde

2016

Titel

Experimental studies of crystal nucleation: metals and colloids

Files

1605.03511v2.pdf

Datenquelle: arXiv

Abstract

Crystallization is one of the most important phase transformations of first order. In the case of metals and alloys, the liquid phase is the parent phase of materials production. The conditions of the crystallization process control the as-solidified material in its chemical and physical properties. Nucleation initiates the crystallization of a liquid. It selects the crystallographic phase, stable or meta-stable. Its detailed knowledge is therefore mandatory for the design of materials. We present techniques of containerless processing for nucleation studies of metals and alloys. We demonstrate the power of these methods for crystal nucleation of stable solids but in particular also for investigations of crystal nucleation of metastable solids at extreme undercooling. This concerns the issue of heterogeneous versus homogeneous nucleation and non-equilibrium conditions. The results are analyzed within classical nucleation theory, where the activation energy of homogeneous nucleation depends on the interfacial energy and the difference of Gibbs free energies of solid and liquid. The interfacial energy acts as barrier for the nucleation process. Its experimental determination is difficult in the case of metals. In the second part of this work we therefore explore the use of colloidal suspensions as models for the crystallization process. Their nucleation process is observed in situ by optical techniques and ultra-small angle X-ray diffraction using high intensity synchrotron radiation. It allows an unambiguous discrimination of homogeneous and heterogeneous nucleation as well as the determination of the interfacial free energy of the solid-liquid interface. Our results are used to construct Turnbull plots of colloids, which are discussed in relation to Turnbull plots of metals and support the hypothesis that colloids are useful model systems to investigate crystal nucleation.

Autoren

Diter M Herlach
Thomas Palberg

DOI

10.1063/1.4963684

ISSN

0021-9606

Zeitschrift

The Journal of Chemical Physics

Notes

keywords: Physics - Materials Science file: https://arxiv.org/pdf/1605.03511v2.pdf file: https://arxiv.org/pdf/1605.03511v2.pdf

Artikelnummer

21

Paginierung

211703 - 211703

Datum der Veröffentlichung

2016

Herausgeber URL

http://arxiv.org/pdf/1605.03511v2

Datum der Datenerfassung

2020

Titel

Experimental studies of crystal nucleation: metals and colloids

Sub types

article

Ausgabe der Zeitschrift

145

Datenquelle: Manual

Experimental studies of crystal nucleation: metals and colloids

Files

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