Abstract
The Johari-Goldstein secondary (b) relaxations are an intrinsic feature of supercooled liquids and glasses. They are crucial to many properties of glassy materials, but the underlying mechanisms are still not established. In a model metallic glass, we study the atomic rearrangements by molecular dynamics simulations at time scales of up to microseconds. We find that the distributions of single-particle displacements exhibit multiple peaks, whose positions quantitatively match the pair distribution function. These are identified as the structural signature of cooperative string-like excitations. Furthermore, the most probable time of the string-like motions coincides with the b-relaxation time as probed by dynamical mechanical simulations over a wide temperature range and is consistent with a theoretical model. Our results provide insights into the long-standing puzzle regarding the structural origin of b relaxations in glassy metallic materials.
| Original language | English (US) |
|---|---|
| Article number | e1701577 |
| Journal | Science advances |
| Volume | 3 |
| Issue number | 11 |
| DOIs | |
| State | Published - Jan 1 2017 |
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Structural rearrangements governing Johari-Goldstein relaxations in metallic glasses. / Yu, Hai Bin; Richert, Ranko; Samwer, Konrad.
In: Science advances, Vol. 3, No. 11, e1701577, 01.01.2017.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Structural rearrangements governing Johari-Goldstein relaxations in metallic glasses
AU - Yu, Hai Bin
AU - Richert, Ranko
AU - Samwer, Konrad
PY - 2017/1/1
Y1 - 2017/1/1
N2 - The Johari-Goldstein secondary (b) relaxations are an intrinsic feature of supercooled liquids and glasses. They are crucial to many properties of glassy materials, but the underlying mechanisms are still not established. In a model metallic glass, we study the atomic rearrangements by molecular dynamics simulations at time scales of up to microseconds. We find that the distributions of single-particle displacements exhibit multiple peaks, whose positions quantitatively match the pair distribution function. These are identified as the structural signature of cooperative string-like excitations. Furthermore, the most probable time of the string-like motions coincides with the b-relaxation time as probed by dynamical mechanical simulations over a wide temperature range and is consistent with a theoretical model. Our results provide insights into the long-standing puzzle regarding the structural origin of b relaxations in glassy metallic materials.
AB - The Johari-Goldstein secondary (b) relaxations are an intrinsic feature of supercooled liquids and glasses. They are crucial to many properties of glassy materials, but the underlying mechanisms are still not established. In a model metallic glass, we study the atomic rearrangements by molecular dynamics simulations at time scales of up to microseconds. We find that the distributions of single-particle displacements exhibit multiple peaks, whose positions quantitatively match the pair distribution function. These are identified as the structural signature of cooperative string-like excitations. Furthermore, the most probable time of the string-like motions coincides with the b-relaxation time as probed by dynamical mechanical simulations over a wide temperature range and is consistent with a theoretical model. Our results provide insights into the long-standing puzzle regarding the structural origin of b relaxations in glassy metallic materials.
UR - http://www.scopus.com/inward/record.url?scp=85041930781&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85041930781&partnerID=8YFLogxK
U2 - 10.1126/sciadv.1701577
DO - 10.1126/sciadv.1701577
M3 - Article
C2 - 29159283
AN - SCOPUS:85041930781
VL - 3
JO - Science advances
JF - Science advances
SN - 2375-2548
IS - 11
M1 - e1701577
ER -