TU Darmstadt / ULB / TUbiblio

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

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

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.

Item Type: Article
Erschienen: 2016
Creators: Adjaoud, Omar and Albe, Karsten
Title: Interfaces and interphases in nanoglasses: Surface segregation effects and their implications on structural properties
Language: English
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.

Journal or Publication Title: Acta Materialia
Volume: 113
Uncontrolled Keywords: Nanoglasses; Metallic glasses; Surface segregation; Nanoparticles; Interfaces; Molecular dynamics
Divisions: 11 Department of Materials and Earth Sciences
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences > Material Science > Materials Modelling
Zentrale Einrichtungen > University IT-Service and Computing Centre (HRZ) > Hochleistungsrechner
Zentrale Einrichtungen > University IT-Service and Computing Centre (HRZ)
Zentrale Einrichtungen
Date Deposited: 19 May 2016 09:31
Official URL: http://dx.doi.org/10.1016/j.actamat.2016.05.002
Identification Number: doi:10.1016/j.actamat.2016.05.002
Funders: The authors acknowledge the financial support of the Deutsche Forschungsgemeinschaft (DFG) through project Grant AL 578/15-1 and AL 578/6-2.
Export:

Optionen (nur für Redakteure)

View Item View Item