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Interfaces and interphases in nanoglasses: Surface segregation effects and their implications on structural properties

Adjaoud, Omar ; Albe, Karsten :
Interfaces and interphases in nanoglasses: Surface segregation effects and their implications on structural properties.
[Online-Edition: http://dx.doi.org/10.1016/j.actamat.2016.05.002]
In: Acta Materialia, 113 pp. 284-292. ISSN 13596454
[Artikel], (2016)

Offizielle URL: http://dx.doi.org/10.1016/j.actamat.2016.05.002

Kurzbeschreibung (Abstract)

Metallic nanoglasses can be prepared by cold compaction of amorphous nanoparticles initially condensed in inert gas atmosphere. Experimentally, it has been found that a characteristic feature of nanoglasses is the occurrence of atomic density variations within the microstructure, that cannot be explained by interface induced topological variations in a chemically homogeneous material. Here we present molecular dynamics simulations, which reveal that compositional variations between glass-glass interfaces and the volume material can result from surface segregation effects already present in the primary particles. By comparing results for Pd80Si20 and Cu64Zr36 metallic glasses, we show that amorphous nanoparticles install an inhomogenous elemental equilibrium distribution in the gas phase before they undergo the glass transition into the solid state. A detailed analysis of planar interfaces generated by merging chemically equilibrated surfaces shows that glass-glass interfaces can be understood as interphases of different composition and short-range order, where the local topology, free volume and local composition are intimately linked.

Typ des Eintrags: Artikel
Erschienen: 2016
Autor(en): Adjaoud, Omar ; Albe, Karsten
Titel: Interfaces and interphases in nanoglasses: Surface segregation effects and their implications on structural properties
Sprache: Englisch
Kurzbeschreibung (Abstract):

Metallic nanoglasses can be prepared by cold compaction of amorphous nanoparticles initially condensed in inert gas atmosphere. Experimentally, it has been found that a characteristic feature of nanoglasses is the occurrence of atomic density variations within the microstructure, that cannot be explained by interface induced topological variations in a chemically homogeneous material. Here we present molecular dynamics simulations, which reveal that compositional variations between glass-glass interfaces and the volume material can result from surface segregation effects already present in the primary particles. By comparing results for Pd80Si20 and Cu64Zr36 metallic glasses, we show that amorphous nanoparticles install an inhomogenous elemental equilibrium distribution in the gas phase before they undergo the glass transition into the solid state. A detailed analysis of planar interfaces generated by merging chemically equilibrated surfaces shows that glass-glass interfaces can be understood as interphases of different composition and short-range order, where the local topology, free volume and local composition are intimately linked.

Titel der Zeitschrift, Zeitung oder Schriftenreihe: Acta Materialia
Band: 113
Freie Schlagworte: Nanoglasses; Metallic glasses; Surface segregation; Nanoparticles; Interfaces; Molecular dynamics
Fachbereich(e)/-gebiet(e): 11 Fachbereich Material- und Geowissenschaften
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Materialmodellierung
Zentrale Einrichtungen > Hochschulrechenzentrum (HRZ) > Hochleistungsrechner
Hinterlegungsdatum: 19 Mai 2016 09:31
Offizielle URL: http://dx.doi.org/10.1016/j.actamat.2016.05.002
ID-Nummer: 10.1016/j.actamat.2016.05.002
Sponsoren: The authors acknowledge the financial support of the Deutsche Forschungsgemeinschaft (DFG) through project Grant AL 578/15-1 and AL 578/6-2.
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