1
|
Yu HB, Gao L, Gao JQ, Samwer K. Universal origin of glassy relaxation as recognized by configuration pattern matching. Natl Sci Rev 2024; 11:nwae091. [PMID: 38577671 PMCID: PMC10989661 DOI: 10.1093/nsr/nwae091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/28/2024] [Accepted: 03/07/2024] [Indexed: 04/06/2024] Open
Abstract
Relaxation processes are crucial for understanding the structural rearrangements of liquids and amorphous materials. However, the overarching principle that governs these processes across vastly different materials remains an open question. Substantial analysis has been carried out based on the motions of individual particles. Here, as an alternative, we propose viewing the global configuration as a single entity. We introduce a global order parameter, namely the inherent structure minimal displacement (IS Dmin), to quantify the variability of configurations by a pattern-matching technique. Through atomic simulations of seven model glass-forming liquids, we unify the influences of temperature, pressure and perturbation time on the relaxation dissipation, via a scaling law between the mechanical damping factor and IS Dmin. Fundamentally, this scaling reflects the curvature of the local potential energy landscape. Our findings uncover a universal origin of glassy relaxation and offer an alternative approach to studying disordered systems.
Collapse
Affiliation(s)
- Hai-Bin Yu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Liang Gao
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jia-Qi Gao
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Konrad Samwer
- I. Physikalisches Institut, Universität Göttingen, Göttingen D-37077, Germany
| |
Collapse
|
2
|
Zella L, Moon J, Egami T. Ripples in the bottom of the potential energy landscape of metallic glass. Nat Commun 2024; 15:1358. [PMID: 38355602 PMCID: PMC10866862 DOI: 10.1038/s41467-024-45640-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 01/29/2024] [Indexed: 02/16/2024] Open
Abstract
In the absence of periodicity, the structure of glass is ill-defined, and a large number of structural states are found at similar energy levels. However, little is known about how these states are connected to each other in the potential energy landscape. We simulate mechanical relaxation by molecular dynamics for a prototypical [Formula: see text] metallic glass and follow the mechanical energy loss of each atom to track the change in the state. We find that the energy barriers separating these states are remarkably low, only of the order of 1 meV, implying that even quantum fluctuations can overcome these potential energy barriers. Our observation of numerous small ripples in the bottom of the potential energy landscape puts many assumptions regarding the thermodynamic states of metallic glasses into question and suggests that metallic glasses are not totally frozen at the local atomic level.
Collapse
Affiliation(s)
- Leo Zella
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Jaeyun Moon
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Takeshi Egami
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN, 37996, USA.
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, 37996, USA.
| |
Collapse
|
3
|
Wang Y, Liu J, Jiang JZ, Cai W. Anomalous temperature dependence of elastic limit in metallic glasses. Nat Commun 2024; 15:171. [PMID: 38167242 PMCID: PMC10761975 DOI: 10.1038/s41467-023-44048-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 11/28/2023] [Indexed: 01/05/2024] Open
Abstract
Understanding the atomistic mechanisms of inelastic deformation in metallic glasses (MGs) remains challenging due to their amorphous structure, where local carriers of plasticity cannot be easily defined. Using molecular dynamics (MD) simulations, we analyzed the onset of inelastic deformation in CuZr MGs, specifically the temperature dependence of the elastic limit, in terms of localized shear transformation (ST) events. We find that although the ST events initiate at lower strain with increasing temperature, the elastic limit increases with temperature in certain temperature ranges. We explain this anomalous behavior through the framework of an energy-strain landscape (ESL) constructed from high-throughput strain-dependent energy barrier calculations for the ST events identified in the MD simulations. The ESL reveals that the anomalous behavior is caused by the transition of ST events from irreversible to reversible with increasing temperature. An analytical formulation is developed to predict this transition and the temperature dependence of the elastic limit.
Collapse
Affiliation(s)
- Yifan Wang
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Jing Liu
- International Center for New-Structured Materials (ICNSM), and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, PR China
| | - Jian-Zhong Jiang
- International Center for New-Structured Materials (ICNSM), and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, PR China.
- School of Materials Science and Engineering, Fuyao University of Science and Technology, Fuzhou, Fujian, PR China.
| | - Wei Cai
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA.
| |
Collapse
|
4
|
Gupta S, Yang X, Ceder G. What dictates soft clay-like lithium superionic conductor formation from rigid salts mixture. Nat Commun 2023; 14:6884. [PMID: 37898616 PMCID: PMC10613223 DOI: 10.1038/s41467-023-42538-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 10/11/2023] [Indexed: 10/30/2023] Open
Abstract
Soft clay-like Li-superionic conductors, integral to realizing all-solid-state batteries, have been recently synthesized by mixing rigid-salts. Here, through computational and experimental analysis, we clarify how a soft clay-like material can be created from a mixture of rigid-salts. Using molecular dynamics simulations with a deep learning-based interatomic potential energy model, we uncover the microscopic features responsible for soft clay-formation from ionic solid mixtures. We find that salt mixtures capable of forming molecular solid units on anion exchange, along with the slow kinetics of such reactions, are key to soft-clay formation. Molecular solid units serve as sites for shear transformation zones, and their inherent softness enables plasticity at low stress. Extended X-ray absorption fine structure spectroscopy confirms the formation of molecular solid units. A general strategy for creating soft clay-like materials from ionic solid mixtures is formulated.
Collapse
Affiliation(s)
- Sunny Gupta
- Department of Materials Science & Engineering, University of California Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Xiaochen Yang
- Department of Materials Science & Engineering, University of California Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Gerbrand Ceder
- Department of Materials Science & Engineering, University of California Berkeley, Berkeley, CA, 94720, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| |
Collapse
|
5
|
Kura C, Wakeda M, Hayashi K, Ohmura T. Energetic and atomic structural analyses of the screw dislocation absorption at tilt grain boundaries in BCC-Fe. Sci Rep 2022; 12:21301. [PMID: 36494412 PMCID: PMC9734193 DOI: 10.1038/s41598-022-25066-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 11/24/2022] [Indexed: 12/13/2022] Open
Abstract
The dislocation-grain boundary (GB) interaction plays an important role in GB-related plasticity. Therefore, an atomistic investigation of the interaction provides a deeper understanding of the strength and fracture of polycrystalline metals. In this study, we investigated the absorption of a screw dislocation with a Burgers vector perpendicular to the GB normal and the corresponding symmetric tilt grain boundaries (STGBs) in BCC-Fe based on molecular static simulations focusing on the STGB-dislocation interaction energy and atomistic structural changes at GB. The STGB-screw dislocation interaction depends on the energetical stability of the STGB against the GB shift along the Burgers vector direction. When the interaction exhibited a large attractive interaction energy, the dislocation dissociation and the GB shift along the Burgers vector direction occurred simultaneously. The interaction energy reveals that the interaction depends on the energetical stability of the STGB in terms of the GB shift in addition to the geometrical descriptor of the GB type, such as the Σ value. The same behavior was also obtained in the reaction when the second dislocation was introduced. We also discuss the screw dislocation absorption and rearrangement of the GB atomistic structure in STGB from an energetic viewpoint.
Collapse
Affiliation(s)
- Chiharu Kura
- Applied Physics Research Laboratory, Kobe Steel, Ltd., 1-5-5 Takatsukadai, Nishi-ku, Kobe, 651-2271, Japan.
| | - Masato Wakeda
- Research Center for Structural Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan.
| | - Kazushi Hayashi
- Applied Physics Research Laboratory, Kobe Steel, Ltd., 1-5-5 Takatsukadai, Nishi-ku, Kobe, 651-2271, Japan
| | - Takahito Ohmura
- Research Center for Structural Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| |
Collapse
|
6
|
Chen G, Qu CK, Gong P. Anomalous diffusion dynamics of learning in deep neural networks. Neural Netw 2022; 149:18-28. [DOI: 10.1016/j.neunet.2022.01.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 12/17/2021] [Accepted: 01/26/2022] [Indexed: 11/17/2022]
|
7
|
Liu C, Fan Y. Emergent Fractal Energy Landscape as the Origin of Stress-Accelerated Dynamics in Amorphous Solids. PHYSICAL REVIEW LETTERS 2021; 127:215502. [PMID: 34860096 DOI: 10.1103/physrevlett.127.215502] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/23/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
The ageing dynamics in a multiplicity of metastable glasses are investigated at various thermomechanical conditions. By using data analytics to deconvolute the integral effects of environmental factors (e.g., energy level, temperature, stress), and by directly scrutinizing the minimum energy pathways for local excitations, we demonstrate external shear would make the system's energy landscape surprisingly fractal and create an emergent low-barrier mode with highly tortuous pathways, leading to an accelerated relaxation. This finding marks a departure from the classic picture of shear-induced simple bias of energy landscape. The insights and implications of this study are also discussed.
Collapse
Affiliation(s)
- Chaoyi Liu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Yue Fan
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| |
Collapse
|
8
|
Shrivastav GP, Kahl G. On the yielding of a point-defect-rich model crystal under shear: insights from molecular dynamics simulations. SOFT MATTER 2021; 17:8536-8552. [PMID: 34505613 PMCID: PMC8480408 DOI: 10.1039/d1sm00662b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/31/2021] [Indexed: 06/13/2023]
Abstract
In real crystals and at finite temperatures point defects are inevitable. Under shear their dynamics severely influence the mechanical properties of these crystals, giving rise to non-linear effects, such as ductility. In an effort to elucidate the complex behavior of crystals under plastic deformation it is crucial to explore and to understand the interplay between the timescale related to the equilibrium point-defect diffusion and the shear-induced timescale. Based on extensive non-equilibrium molecular dynamics simulations we present a detailed investigation on the yielding behavior of cluster crystals, an archetypical model for a defect-rich crystal: in such a system clusters of overlapping particles occupy the lattice sites of a regular (FCC) structure. In equilibrium particles diffuse via site-to-site hopping while maintaining the crystalline structure intact. We investigate these cluster crystals at a fixed density and at different temperatures where the system remains in the FCC structure: temperature allows us to vary the diffusion timescale appropriately. We then expose the crystal to shear, thereby choosing shear rates which cover timescales that are both higher and lower than the equilibrium diffusion timescales. We investigate the macroscopic and microscopic response of our cluster crystal to shear and find that the yielding scenario of such a system does not rely on the diffusion of the particles - it is rather related to the plastic deformation of the underlying crystalline structure. The local bond order parameters and the measurement of local angles between neighboring clusters confirm the cooperative movement of the clusters close to the yield point. Performing complementary, related simulations for an FCC crystal formed by harshly repulsive particles reveals similarities in the yielding behavior between both systems. Still we find that the diffusion of particles does influence characteristic features in the cluster crystal, such as a less prominent increase of order parameters close to the yield point. Our simulations provide for the first time an insight into the role of the diffusion of defects in the yielding behavior of a defect-rich crystal under shear. These observations will thus be helpful in the development of theories for the plastic deformation of defect-rich crystals.
Collapse
Affiliation(s)
- Gaurav P Shrivastav
- Institut für Theoretische Physik and Center for Computational Materials Science (CMS), TU Wien, Wiedner Hauptstraße 8-10, A-1040 Wien, Austria.
| | - Gerhard Kahl
- Institut für Theoretische Physik and Center for Computational Materials Science (CMS), TU Wien, Wiedner Hauptstraße 8-10, A-1040 Wien, Austria.
| |
Collapse
|
9
|
Ohzono T, Katoh K, Minamikawa H, Saed MO, Terentjev EM. Internal constraints and arrested relaxation in main-chain nematic elastomers. Nat Commun 2021; 12:787. [PMID: 33542238 PMCID: PMC7862651 DOI: 10.1038/s41467-021-21036-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/04/2021] [Indexed: 11/16/2022] Open
Abstract
Nematic liquid crystal elastomers (N-LCE) exhibit intriguing mechanical properties, such as reversible actuation and soft elasticity, which manifests as a wide plateau of low nearly-constant stress upon stretching. N-LCE also have a characteristically slow stress relaxation, which sometimes prevents their shape recovery. To understand how the inherent nematic order retards and arrests the equilibration, here we examine hysteretic stress-strain characteristics in a series of specifically designed main-chain N-LCE, investigating both macroscopic mechanical properties and the microscopic nematic director distribution under applied strains. The hysteretic features are attributed to the dynamics of thermodynamically unfavoured hairpins, the sharp folds on anisotropic polymer strands, the creation and transition of which are restricted by the nematic order. These findings provide a new avenue for tuning the hysteretic nature of N-LCE at both macro- and microscopic levels via different designs of polymer networks, toward materials with highly nonlinear mechanical properties and shape-memory applications.
Collapse
Affiliation(s)
- Takuya Ohzono
- Research Institute for Electronics and Photonics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.
| | - Kaoru Katoh
- Biomedical Research Institute, AIST, Tsukuba, Japan
| | | | - Mohand O Saed
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | |
Collapse
|
10
|
Yang J, Duan J, Wang YJ, Jiang MQ. Complexity of plastic instability in amorphous solids: Insights from spatiotemporal evolution of vibrational modes. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2020; 43:56. [PMID: 32920738 DOI: 10.1140/epje/i2020-11983-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 08/19/2020] [Indexed: 06/11/2023]
Abstract
It has been accepted that low-frequency vibrational modes are causally correlated to fundamental plastic rearrangement events in amorphous solids, irrespective of the structural details. But the mode-event relationship is far from clear. In this work, we carry out case studies using atomistic simulations of a three-dimensional Cu50Zr50 model glass under athermal, quasistatic shear. We focus on the first four plastic events, and carefully trace the spatiotemporal evolution of the associated low-frequency normal modes with applied shear strain. We reveal that these low-frequency modes get highly entangled with each other, from which the critical mode emerges spontaneously to predict a shear transformation event. But the detailed emergence picture is event by event and shear-protocol dependent, even for the first plastic event. This demonstrates that the instability of a plastic event is a result of extremely complex multiple-path choice or competition, and there is a strong, elastic interaction among neighboring instability events. At last, the generality of the present findings is shown to be applicable to covalent-bonded glasses.
Collapse
Affiliation(s)
- J Yang
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, 100190, Beijing, China
| | - J Duan
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Engineering Science, University of Chinese Academy of Sciences, 101408, Beijing, China
| | - Y J Wang
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Engineering Science, University of Chinese Academy of Sciences, 101408, Beijing, China
| | - M Q Jiang
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, 100190, Beijing, China.
- School of Engineering Science, University of Chinese Academy of Sciences, 101408, Beijing, China.
| |
Collapse
|