
The Nanoscale Density Gradient as a Structural Stabilizer for Glass Formation
Shaoxiong Zhou, Bangshao Dong, Yanguo Wang, Jingyu Qin, Weihua Wang
Engineering ›› 2023, Vol. 29 ›› Issue (10) : 120-129.
The Nanoscale Density Gradient as a Structural Stabilizer for Glass Formation
The rapid cooling of a metallic liquid (ML) results in short-range order (SRO) among the atomic arrangements and a disordered structure in the resulting metallic glass (MG). These phenomena cause various possible features in the microscopic structure of the MG, presenting a puzzle about the nature of the MGs’ microscopic structure beyond SRO. In this study, the nanoscale density gradient (NDG) originating from a sequential arrangement of clusters with different atomic packing densities (APDs), representing the medium-range structural heterogeneity in Zr60Cu30Al10 MG, was characterized using electron tomography (ET) combined with image simulations based on structure modeling. The coarse polyhedrons with distinct facets identified in the three-dimensional images coincide with icosahedron-like clusters and represent the spatial positions of clusters with high APDs. Rearrangements of the different clusters according to descending APD order in the glass-forming process are responsible for the NDG that stabilizes both the supercooled ML and the amorphous states and acts as a hidden rule in the transition from ML to MG.
Rapid cooling / Amorphous solid / Density gradient / Electron tomography / Atomic clusters
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[4] |
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[5] |
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[6] |
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[7] |
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[8] |
|
[9] |
|
[10] |
|
[11] |
|
[12] |
|
[13] |
|
[14] |
|
[15] |
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[16] |
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[17] |
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[18] |
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[19] |
|
[20] |
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[21] |
|
[22] |
|
[23] |
|
[24] |
|
[25] |
|
[26] |
|
[27] |
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[28] |
|
[29] |
|
[30] |
|
[31] |
|
[32] |
|
[33] |
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[34] |
|
[35] |
|
[36] |
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[37] |
|
[38] |
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[39] |
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[40] |
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[41] |
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[42] |
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[43] |
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[44] |
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[45] |
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[46] |
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This work was supported by the National Natural Science Foundation of China (51971093, 52192603, and 51501043).
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