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Atomic Structure and Structural Stability of Sc75Fe25Nanoglasses

Fang, J. X. and Vainio, U. and Puff, W. and Würschum, R. and Wang, X. L. and Wang, D. and Ghafari, M. and Jiang, F. and Sun, J. and Hahn, H. and Gleiter, H. (2012):
Atomic Structure and Structural Stability of Sc75Fe25Nanoglasses.
In: Nano Letters, ACS Publications, pp. 458-463, 12, (1), ISSN 1530-6984,
[Online-Edition: http://dx.doi.org/10.1021/nl2038216],
[Article]

Abstract

Nanoglasses are solids consisting of nanometer-sized glassy regions connected by interfaces having a reduced density. We studied the structure of Sc75Fe25 nanoglasses by electron microscopy, positron annihilation spectroscopy, and small-/wide-angle X-ray scattering. The positron annihilation spectroscopy measurements showed that the as-prepared nanoglasses consisted of 65 vol% glassy and 35 vol% interfacial regions. By applying temperature annealing to the nanoglasses and measuring in situ small-angle X-ray scattering, we observed that the width of the interfacial regions increased exponentially as a function of the annealing temperature. A quantitative fit to the small-angle X-ray scattering data using a Debye–Bueche random phase model gave a correlation length that is related to the sizes of the interfacial regions in the nanoglass. The correlation length was found to increase exponentially from 1.3 to 1.7 nm when the sample temperature was increased from 25 to 230 °C. Using simple approximations, we correlate this to an increase in the width of interfacial regions from 0.8 to 1.2 nm, while the volume fraction of interfacial regions increased from 31 to 44%. Using micro-compression measurements, we investigated the deformation behavior of ribbon glass and the corresponding nanoglass. While the nanoglass exhibited a remarkable plasticity even in the annealed state owing to the glass-glass interfaces, the corresponding ribbon glass was brittle. As this difference seems not limited to Sc75Fe25 glasses, the reported result suggest that nanoglasses open the way to glasses with high ductility resulting from the nanometer sized microstructure.

Item Type: Article
Erschienen: 2012
Creators: Fang, J. X. and Vainio, U. and Puff, W. and Würschum, R. and Wang, X. L. and Wang, D. and Ghafari, M. and Jiang, F. and Sun, J. and Hahn, H. and Gleiter, H.
Title: Atomic Structure and Structural Stability of Sc75Fe25Nanoglasses
Language: English
Abstract:

Nanoglasses are solids consisting of nanometer-sized glassy regions connected by interfaces having a reduced density. We studied the structure of Sc75Fe25 nanoglasses by electron microscopy, positron annihilation spectroscopy, and small-/wide-angle X-ray scattering. The positron annihilation spectroscopy measurements showed that the as-prepared nanoglasses consisted of 65 vol% glassy and 35 vol% interfacial regions. By applying temperature annealing to the nanoglasses and measuring in situ small-angle X-ray scattering, we observed that the width of the interfacial regions increased exponentially as a function of the annealing temperature. A quantitative fit to the small-angle X-ray scattering data using a Debye–Bueche random phase model gave a correlation length that is related to the sizes of the interfacial regions in the nanoglass. The correlation length was found to increase exponentially from 1.3 to 1.7 nm when the sample temperature was increased from 25 to 230 °C. Using simple approximations, we correlate this to an increase in the width of interfacial regions from 0.8 to 1.2 nm, while the volume fraction of interfacial regions increased from 31 to 44%. Using micro-compression measurements, we investigated the deformation behavior of ribbon glass and the corresponding nanoglass. While the nanoglass exhibited a remarkable plasticity even in the annealed state owing to the glass-glass interfaces, the corresponding ribbon glass was brittle. As this difference seems not limited to Sc75Fe25 glasses, the reported result suggest that nanoglasses open the way to glasses with high ductility resulting from the nanometer sized microstructure.

Journal or Publication Title: Nano Letters
Volume: 12
Number: 1
Publisher: ACS Publications
Uncontrolled Keywords: Nanoglass, metallic glass, small-angle X-ray scattering, wide-angle X-ray scattering, positron annihilation spectroscopy, interface delocalization, mechanical property
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Joint Research Laboratory Nanomaterials
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences
Date Deposited: 16 Jun 2014 11:58
Official URL: http://dx.doi.org/10.1021/nl2038216
Identification Number: doi:10.1021/nl2038216
Funders: This work was supported by the Deutsche Forschungsgemein- schaft (DFG) under contract HA 1344/23-1., We thank Alexander-von- Humboldt Foundation for a fellowship, and the NES Program at KIT for support. , .X. Fang was supported by National Natural Science Foundation of China (No. 51171139), Doctoral Fund for New Teachers (No.20110201120039), Tengfei Talent Project of Xi ’ an Jiaotong University, the New Century Excellent Talents in University (NCET)., And the Fundamental Research Funds for the Central Universities (No 08142008), F. Jiang was supported by the National Natural Science Foundation of China under Grant Nos.50871079., J. Sun also wish to express his special thanks for the support from the National Basic Research Program of China (Grant No. 2010CB631003) as well as 111 Project of China (B06025)., We also thank the support from the XJTU Center for Advancing Materials Performance from the Nanoscale.
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