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β-relaxation and low-temperature aging in a Au-based bulk metallic glass: From elastic properties to atomic-scale structure

Evenson, Z. and Naleway, S. E. and Wei, S. and Gross, O. and Kruzic, J. J. and Gallino, I. and Possart, W. and Stommel, M. and Busch, R. (2014) β-relaxation and low-temperature aging in a Au-based bulk metallic glass: From elastic properties to atomic-scale structure. Physical Review B, 89, p. 174204. American Physical Society. ISSN 1098-0121

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Official URL: http://link.aps.org/doi/10.1103/PhysRevB.89.174204

Abstract

The slow β relaxation is understood to be a universal feature of glassy dynamics. Its presence in bulk metallic glasses (BMGs) is evidence of a broad relaxation time spectrum that extends to deep within the glassy state. Despite the breadth of research devoted to this phenomenon, its microscopic origin is still not fully understood. The low-temperature aging behavior and atomic structural rearrangements of a Au49Cu26.9Si16.3Ag5.5Pd2.3 BMG are investigated in the regime of the slow β relaxation by employing an ensemble of experimental techniques such as high-intensity synchrotron x-ray scattering, modulated differential scanning calorimetry (MDSC), dynamic mechanical analysis (DMA), impulse excitation, and dilatometry. Evidence of a distinct slow β-relaxation regime is seen in the form of (1) an excess wing of the DMA loss modulus beginning at ∼50 ∘C, (2) a crossover effect of elastic modulus with isothermal aging at 50∘C, and (3) a broad, nonreversing and largely irreversible sub-Tg endotherm in the MDSC results. Atomic rearrangements occurring at the onset of the measured slow β-relaxation temperature regime were found to be confined mainly to the short-range order length scale while no significant atomic rearrangements occur on the length scale of the medium-range order. Furthermore, evidence is presented that suggests the crossover effect in Young's modulus is due to the evolution of chemical short-range order. These results support the emergent picture of a dynamically heterogeneous glassy structure, in which low-temperature relaxation occurs through atomic rearrangements confined mostly to the short-range order length scale.

Item URL in elib:https://elib.dlr.de/92245/
Document Type:Article
Title:β-relaxation and low-temperature aging in a Au-based bulk metallic glass: From elastic properties to atomic-scale structure
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Evenson, Z.UNSPECIFIEDUNSPECIFIED
Naleway, S. E.UNSPECIFIEDUNSPECIFIED
Wei, S.UNSPECIFIEDUNSPECIFIED
Gross, O.UNSPECIFIEDUNSPECIFIED
Kruzic, J. J.UNSPECIFIEDUNSPECIFIED
Gallino, I.UNSPECIFIEDUNSPECIFIED
Possart, W.UNSPECIFIEDUNSPECIFIED
Stommel, M.UNSPECIFIEDUNSPECIFIED
Busch, R.UNSPECIFIEDUNSPECIFIED
Date:29 May 2014
Journal or Publication Title:Physical Review B
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:No
Volume:89
Page Range:p. 174204
Publisher:American Physical Society
ISSN:1098-0121
Status:Published
Keywords:bulk metallic glass; beta relaxation; synchrotron x-ray diffraction
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Research under Space Conditions
DLR - Research area:Raumfahrt
DLR - Program:R FR - Forschung unter Weltraumbedingungen
DLR - Research theme (Project):R - Vorhaben Materialwissenschaftliche Forschung (old)
Location: Köln-Porz
Institutes and Institutions:Institute of Materials Physics in Space
Deposited By: Evenson, Zachary
Deposited On:24 Nov 2014 09:49
Last Modified:06 Sep 2019 15:29

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