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del Rio BG, González LE. Exploring Challenging Properties of Liquid Metallic Systems through Machine Learning: Liquid La and Li 4Pb Systems. J Chem Theory Comput 2024; 20:3285-3297. [PMID: 38557035 PMCID: PMC11044274 DOI: 10.1021/acs.jctc.4c00049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 04/04/2024]
Abstract
In this machine learning (ML) study, we delved into the unique properties of liquid lanthanum and the Li4Pb alloy, revealing some unexpected features and also firmly establishing some of the debated characteristics. Leveraging interatomic potentials derived from ab initio calculations, our investigation achieved a level of precision comparable to first-principles methods while at the same time entering the hydrodynamic regime. We compared the structure factors and pair distribution functions to experimental data and unearthed distinctive collective excitations with intriguing features. Liquid lanthanum unveiled two transverse collective excitation branches, each closely tied to specific peaks in the velocity autocorrelation function spectrum. Furthermore, the analysis of the generalized specific heat ratio in the hydrodynamic regime investigated with the ML molecular dynamics simulations uncovered a peculiar behavior, impossible to discern with only ab initio simulations. Liquid Li4Pb, on the other hand, challenged existing claims by showcasing a rich array of branches in its longitudinal dispersion relation, including a high-frequency LiLi mode with a nonhydrodynamic optical character that maintains a finite value as q → 0. Additionally, we conducted an in-depth analysis of various transport coefficients, expanding our understanding of these liquid metallic systems. In summary, our ML approach yielded precise results, offering new and captivating insights into the structural and dynamic aspects of these materials.
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Affiliation(s)
- Beatriz G. del Rio
- Departamento de Física Teórica
Atómica y Óptica, Universidad
de Valladolid, 47011 Valladolid, Spain
| | - Luis E. González
- Departamento de Física Teórica
Atómica y Óptica, Universidad
de Valladolid, 47011 Valladolid, Spain
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2
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Song L, Shao A, Li D, Tian X, Qiao Z, Tang H, Lin X. First-principles study for quasi-static growth model in FeAl intermetallic based on Wulff cluster model. RSC Adv 2024; 14:8116-8123. [PMID: 38464696 PMCID: PMC10921295 DOI: 10.1039/d4ra00853g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/04/2024] [Indexed: 03/12/2024] Open
Abstract
In order to investigate the structure of FeAl mesoscopic crystals segregating in liquid state alloys, we have determined their equilibrium structures (Wulff shape) based on the Wulff cluster model. For non-stoichiometric surface terminations, the chemical environment is taken into account through the chemical potential of the constituents. In this case, different cluster shapes change as a function of the chemical environment. In order to model the growth process in more detail, we propose a quasi-static growth model based on the sequential addition of (sub-)monolayers in the most favorable surface directions. Thus, a sequence of different Wulff shapes results in the growth process, as illustrated for the FeAl intermetallic compound. This model is proved preliminarily by calculating the concentration trend of Al/Fe atoms on both Al-terminated and Fe-terminated surfaces, and by simulating the most stable layer adsorbed on these two surfaces. This model might be helpful in analyzing the growth processes including nucleation barriers during nucleation processes theoretically.
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Affiliation(s)
- Lin Song
- Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 264006 People's Republic of China
| | - Anchen Shao
- Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 264006 People's Republic of China
| | - Dong Li
- Shandong Ludian Line Equipment Co. Ltd China
| | - Xuelei Tian
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University Jinan 250061 People's Republic of China
| | - Zhuhui Qiao
- Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 264006 People's Republic of China
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences Lanzhou 730000 People's Republic of China
| | - Huaguo Tang
- Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 264006 People's Republic of China
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences Lanzhou 730000 People's Republic of China
| | - Xiaohang Lin
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University Jinan 250061 People's Republic of China
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3
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Abstract
Contrary to continuous phase transitions, where renormalization group theory provides a general framework, for discontinuous phase transitions such a framework seems to be absent. Although the thermodynamics of the latter type of transitions is well-known and requires input from two phases, for melting a variety of one-phase theories and models based on solids has been proposed, as a generally accepted theory for liquids is (yet) missing. Each theory or model deals with a specific mechanism using typically one of the various defects (vacancies, interstitials, dislocations, interstitialcies) present in solids. Furthermore, recognizing that surfaces are often present, one distinguishes between mechanical or bulk melting and thermodynamic or surface-mediated melting. After providing the necessary preliminaries, we discuss both types of melting in relation to the various defects. Thereafter we deal with the effect of pressure on the melting process, followed by a discussion along the line of type of materials. Subsequently, some other aspects and approaches are dealt with. An attempt to put melting in perspective concludes this review.
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Affiliation(s)
- Gijsbertus de With
- Laboratory of Physical Chemistry, Eindhoven University of Technology, Het Kranenveld 14, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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4
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Chen FZ, Ruhland K, Umland C, Bertrand SM, Vogt AJ, Kelton KF, Mauro NA. Structural evolution in Au- and Pd-based metallic glass forming liquids and the case for improved molecular dynamics force fields. J Chem Phys 2022; 157:194501. [DOI: 10.1063/5.0123907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The results of a combined experimental and computational investigation of the structural evolution of Au81Si19, Pd82Si18, and Pd77Cu6Si17 metallic glass forming liquids are presented. Electrostatically levitated metallic liquids are prepared, and synchrotron x-ray scattering studies are combined with embedded atom method molecular dynamics simulations to probe the distribution of relevant structural units. Metal–metalloid based metallic glass forming systems are an extremely important class of materials with varied glass forming ability and mechanical processibility. High quality experimental x-ray scattering data are in poor agreement with the data from the molecular dynamics simulations, demonstrating the need for improved interatomic potentials. The first peak in the x-ray static structure factor in Pd77Cu6Si17 displays evidence for a Curie–Weiss type behavior but also a peak in the effective Curie temperature. A proposed order parameter distinguishing glass forming ability, [Formula: see text], shows a peak in the effective Curie temperature near a crossover temperature established by the behavior of the viscosity, T A.
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Affiliation(s)
- F. Z. Chen
- Institute of Materials Science and Engineering, Washington University, St. Louis, Missouri 63130, USA
| | - K. Ruhland
- Department of Physics, St. Norbert College, De Pere, Wisconsin 54115, USA
| | - C. Umland
- Department of Physics, St. Norbert College, De Pere, Wisconsin 54115, USA
| | - S. M. Bertrand
- Department of Physics, St. Norbert College, De Pere, Wisconsin 54115, USA
| | - A. J. Vogt
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - K. F. Kelton
- Institute of Materials Science and Engineering, Washington University, St. Louis, Missouri 63130, USA
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - N. A. Mauro
- Department of Physics, St. Norbert College, De Pere, Wisconsin 54115, USA
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5
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Khusnutdinoff RM, Khairullina RR, Suslov AA, Lad'yanov VI, Mokshin AV. Is icosahedral short-range order presented in supercooled transition metals? J Phys Condens Matter 2022; 34:365403. [PMID: 35764079 DOI: 10.1088/1361-648x/ac7cae] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Supercooled transition metals are characterized by the absence of long-range order and the presence of a specific short-range order in the arrangement of atoms. So, the presence of shoulders and broadenings at the second maximum in the experimentally measured quantity-in the static structure factorS(k)-is usually interpreted as a manifestation of the icosahedral (ideal or distorted) short-range order (ISRO-Icosahedral Short-Range Order). Icosahedral short-range order is a structure with fivefold symmetry in the arrangement of atoms, which can lead to the possibility of achieving deep supercooling. In this work, we study the local structural features of equilibrium and supercooled nickel melts under various cooling protocols (γ∈1010,1014 K s-1) in order to clarify the mechanism of formation of the icosahedral short-range order in pure transition metals. Comprehensive studies of the properties of nickel melts were carried out using experiments on x-ray diffraction, large-scale molecular dynamics (MD) simulations with subsequent structural and cluster analysis. A good agreement was found between the results of x-ray diffraction data and the MD simulations results for an equilibrium nickel melt. It was found that the nickel melt is characterized by a short-range order, formed by fragments of icosahedra and distorted icosahedral clusters. It was revealed that the 'liquid-crystal' phase transition in nickel is accompanied by the transformation of distorted icosahedral clusters into clusters with thefcc/hcp-symmetry. It is shown that, in contrast to the Voronoi tessellation method, the cluster analysis method based on the (q4,q6) rotational invariants does not allow sufficiently correct identification of the distorted icosahedral short-range order in metal melts.
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Affiliation(s)
- R M Khusnutdinoff
- Department of Physics, Kazan (Volga Region) Federal University, Kazan 420008, Russia
- Udmurt Federal Research Center, Ural Branch of Russian Academy of Sciences, Izhevsk 426068, Russia
| | - R R Khairullina
- Department of Physics, Kazan (Volga Region) Federal University, Kazan 420008, Russia
| | - A A Suslov
- Udmurt Federal Research Center, Ural Branch of Russian Academy of Sciences, Izhevsk 426068, Russia
| | - V I Lad'yanov
- Udmurt Federal Research Center, Ural Branch of Russian Academy of Sciences, Izhevsk 426068, Russia
| | - A V Mokshin
- Department of Physics, Kazan (Volga Region) Federal University, Kazan 420008, Russia
- Udmurt Federal Research Center, Ural Branch of Russian Academy of Sciences, Izhevsk 426068, Russia
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Ma C, Song B, Ma Z, Wang X, Tian L, Zhang H, Chen C, Zheng X, Yang LM, Wu Y. A Supported Palladium on Gallium-based Liquid Metal Catalyst for Enhanced Oxygen Reduction Reaction. Chem Res Chin Univ 2022. [DOI: 10.1007/s40242-022-2092-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Yuan Y, Kim DS, Zhou J, Chang DJ, Zhu F, Nagaoka Y, Yang Y, Pham M, Osher SJ, Chen O, Ercius P, Schmid AK, Miao J. Three-dimensional atomic packing in amorphous solids with liquid-like structure. Nat Mater 2022; 21:95-102. [PMID: 34663951 DOI: 10.1038/s41563-021-01114-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
Liquids and solids are two fundamental states of matter. However, our understanding of their three-dimensional atomic structure is mostly based on physical models. Here we use atomic electron tomography to experimentally determine the three-dimensional atomic positions of monatomic amorphous solids, namely a Ta thin film and two Pd nanoparticles. We observe that pentagonal bipyramids are the most abundant atomic motifs in these amorphous materials. Instead of forming icosahedra, the majority of pentagonal bipyramids arrange into pentagonal bipyramid networks with medium-range order. Molecular dynamics simulations further reveal that pentagonal bipyramid networks are prevalent in monatomic metallic liquids, which rapidly grow in size and form more icosahedra during the quench from the liquid to the glass state. These results expand our understanding of the atomic structures of amorphous solids and will encourage future studies on amorphous-crystalline phase and glass transitions in non-crystalline materials with three-dimensional atomic resolution.
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Affiliation(s)
- Yakun Yuan
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Dennis S Kim
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jihan Zhou
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Dillan J Chang
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Fan Zhu
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | | | - Yao Yang
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Minh Pham
- Department of Mathematics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Stanley J Osher
- Department of Mathematics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ou Chen
- Department of Chemistry, Brown University, Providence, RI, USA
| | - Peter Ercius
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Andreas K Schmid
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jianwei Miao
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA.
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8
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Lan S, Zhu L, Wu Z, Gu L, Zhang Q, Kong H, Liu J, Song R, Liu S, Sha G, Wang Y, Liu Q, Liu W, Wang P, Liu CT, Ren Y, Wang XL. A medium-range structure motif linking amorphous and crystalline states. Nat Mater 2021; 20:1347-1352. [PMID: 34017117 DOI: 10.1038/s41563-021-01011-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
Amorphous materials have no long-range order, but there are ordered structures at short range (2-5 Å), medium range (5-20 Å) and even longer length scales1-5. While regular6,7 and semiregular polyhedra8-10 are often found as short-range ordering in amorphous materials, the nature of medium-range order has remained elusive11-14. Consequently, it is difficult to determine whether there exists any structural link at medium range or longer length scales between the amorphous material and its crystalline counterparts. Moreover, an amorphous material often crystallizes into a phase of different composition15, with very different underlying structural building blocks, further compounding the issue. Here, we capture an intermediate crystalline cubic phase in a Pd-Ni-P amorphous alloy and reveal the structure of the medium-range order, a six-membered tricapped trigonal prism cluster (6M-TTP) with a length scale of 12.5 Å. We find that the 6M-TTP can pack periodically to several tens of nanometres to form the cube phase. Our experimental observations provide evidence of a structural link between the amorphous and crystalline phases in a Pd-Ni-P alloy at the medium-range length scale and suggest that it is the connectivity of the 6M-TTP clusters that distinguishes the crystalline and amorphous phases. These findings will shed light on the structure of amorphous materials at extended length scales beyond that of short-range order.
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Affiliation(s)
- Si Lan
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, China.
- Department of Physics, City University of Hong Kong, Kowloon, Hong Kong, China.
| | - Li Zhu
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Zhenduo Wu
- Center for Neutron Scattering and Applied Physics, City University of Hong Kong Dongguan Research Institute, Dongguan, China
| | - Lin Gu
- Beijing National Laboratory for Condensed Matter Physics and Collaborative Innovation Center of Quantum Matter, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics and Collaborative Innovation Center of Quantum Matter, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Huihui Kong
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Jizi Liu
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Ruoyu Song
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Sinan Liu
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Gang Sha
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Yingang Wang
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Qi Liu
- Department of Physics, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Wei Liu
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Peiyi Wang
- SUSTech Cryo-EM Facility Center, Southern University of Science and Technology, Shenzhen, China
| | - Chain-Tsuan Liu
- Center for Advanced Structural Materials & Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Yang Ren
- X-ray Science Division, Argonne National Laboratory, Argonne, IL, USA.
| | - Xun-Li Wang
- Department of Physics, City University of Hong Kong, Kowloon, Hong Kong, China.
- Center for Neutron Scattering, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
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9
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Kang H, Feng S, Li Z, Pan S, Wang L. Anomalies in the dynamics of a metallic glass-forming liquid under super-high pressure. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Parisiades P. A Review of the Melting Curves of Transition Metals at High Pressures Using Static Compression Techniques. Crystals 2021; 11:416. [DOI: 10.3390/cryst11040416] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The accurate determination of melting curves for transition metals is an intense topic within high pressure research, both because of the technical challenges included as well as the controversial data obtained from various experiments. This review presents the main static techniques that are used for melting studies, with a strong focus on the diamond anvil cell; it also explores the state of the art of melting detection methods and analyzes the major reasons for discrepancies in the determination of the melting curves of transition metals. The physics of the melting transition is also discussed.
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Liu H, Xia J, Zhang N, Cheng H, Bi W, Zu X, Chu W, Wu H, Wu C, Xie Y. Solid–liquid phase transition induced electrocatalytic switching from hydrogen evolution to highly selective CO2 reduction. Nat Catal 2021; 4:202-11. [DOI: 10.1038/s41929-021-00576-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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12
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Del Rio BG, Pascual C, González LE, González DJ. Structure and dynamics of the liquid 3d transition metals near melting. An ab initio study. J Phys Condens Matter 2020; 32:214005. [PMID: 31972549 DOI: 10.1088/1361-648x/ab6f16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The static and dynamic properties of several bulk liquid 3d transition metals at thermodynamic conditions near their respective melting points have been evaluated by using ab initio molecular dynamics simulations. The calculated static structure factors show an asymmetric second peak followed by a more or less marked shoulder which points to a sizeable amount of icosahedral local order. Special attention is devoted to the analysis of the longitudinal and transverse current spectral functions and the corresponding dispersion of collective excitations. For some metals, we have found the existence of two branches of transverse collective excitations in the second pseudo-Brillouin zone. Finally, results are also reported for several transport coefficients.
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Affiliation(s)
- Beatriz G Del Rio
- Departamento de Física Teórica, Universidad de Valladolid, Valladolid, Spain
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13
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Abstract
The relationship between the excess volume and the structure of Fe-Cr-Ni melts is investigated using containerless levitation and in situ high-energy synchrotron x-ray diffraction techniques. The density of six hypoeutectic Fe-Cr-Ni alloys along the 72 wt. % Fe isopleth was measured in the stable and undercooled regions, and the excess volume was evaluated as a function of Cr concentration. It is found that the 72Fe-Cr-Ni alloys exhibit a positive sign of excess volume and the amount increases with increasing Cr concentration. Analysis of the structure factor and pair distribution function of the alloy family reveals that the short-range order in the melt becomes more pronounced with decreasing Cr concentration; this demonstrates a direct correlation between the excess volume and local liquid structure. A characteristic signature of the icosahedral structure is observed in the structure factor of the melts, and the potential origin of the positive excess volume of the 72Fe-Cr-Ni alloys is qualitatively discussed in relation to the icosahedral structure.
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Affiliation(s)
- Sangho Jeon
- Department of Mechanical Engineering, Tufts University, Medford, Massachusetts 02155, USA
| | | | - Olga Shuleshova
- IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden, Germany
| | - Ivan Kaban
- IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden, Germany
| | - Douglas M Matson
- Department of Mechanical Engineering, Tufts University, Medford, Massachusetts 02155, USA
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14
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Abstract
The electronic structure of A7C (A = Hg, Pd, V, Cr, Mn, Fe, Ni, Cu; C = 0, ±1, ±2) clusters has been determined using density functional theory methods. The A7C (A = Hg, Pd, Cr, Cu; C = 0, ±1, ±2) clusters all conform to the existing superatomic model, with a sufficiently stabilised local structure to prevent perturbation upon the introduction of exact exchange to the exchange correlation functional. For the A7C (A = Mn, Fe, Ni; C = 0, ±1, ±2) clusters the incorporation of exact exchange separates the atomic s- and d-electrons, leading to a net increase in the number of superatomic electrons. Conversely the incorporation of exact exchange into the exchange correlation functional decreases the number of superatomic electrons for the V7C (C = 0, ±1, ±2) clusters, owing to the radial extension of the d-orbitals influencing their ability to contribute into superatomic shells.
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Affiliation(s)
- J T A Gilmour
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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15
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Zhang W, Wang X, Cao QP, Zhang D, Jiang JZ. Temperature Dependences of Peak Positions in Pair Distribution Function of Metallic Liquids. J Phys Chem B 2019; 123:7055-7060. [PMID: 31365259 DOI: 10.1021/acs.jpcb.9b05258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The temperature dependences of the peak positions in pair distribution functions G(r) of pure metallic zinc (Zn) and indium (In) liquids have been studied using high-energy X-ray diffraction together with ab initio molecular dynamic simulations. It has been demonstrated that the first peak positions in G(r) of both Zn and In move to small r, whereas the second peak positions exhibit opposite movements with increasing temperature, originating from different thermal responses of polyhedron connections. However, the third, above peaks in G(r) in both liquids shift to large r with the expansion coefficients smaller than the values of bulk liquids.
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16
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Abstract
The geometries and electronic structures of small M7C (M = Sc, Y, La, Ti, Zr, Hf; C = 0, ±1, ±2) clusters have been calculated at a range of multiplicities at each cluster charge, using density functional theory methods. These clusters conform to the existing superatom model, with some contextual differences. There are a range of states which are populated by the outermost s and d-electrons of the constituent atoms, with an irregular Aufbau rule for the states formed from the atomic d-electrons. The states comprised of d-electrons present themselves as two states of P-symmetry and two states of F-symmetry, which are nearly degenerate, followed by states of D-symmetry, a shell ordering which arises due to the symmetry, and favourable overlap, of the contributing states. The effect of exact exchange in modulating the localisation of these states is also discussed. In addition, this study shows pseudo-superatomic states which arise due to the 5-fold symmetry of the clusters, materialising as either a ring or plane of electron density. In summary, these observations allow for an expansion of the role that early transition metals have within the existing superatom framework.
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Affiliation(s)
- J T A Gilmour
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | - N Gaston
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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17
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Holland-Moritz D, Nowak B, Yang F, Meyer A. Structure and dynamics of glass-forming alloy melts investigated by application of levitation techniques. PURE APPL CHEM 2019. [DOI: 10.1515/pac-2018-0907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In this work results of studies on the short-range order and on the atomic dynamics in different stable and undercooled glass-forming metallic melts are reviewed. In order to undercool the melts deeply below the melting temperature and to avoid chemical reactions of the melts with crucible materials, the samples are containerlessly processed utilizing the electromagnetic or the electrostatic levitation technique. The short-range structure of the melts is studied by neutron diffraction, while the atomic dynamics are investigated by quasielastic neutron scattering. The relationship between short-range structure and atomic dynamics is discussed within the mode coupling theory of the glass transition. We will show that taking the time- and space-averaged structural information provided by measured partial structure factors as an input, mode coupling theory is able to explain the experimental results concerning the activation energies for self-diffusion and the coupling/decoupling behavior of the self-diffusion coefficients of the different alloy components.
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Affiliation(s)
- Dirk Holland-Moritz
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR) , 51170 Köln , Germany
| | - Benedikt Nowak
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR) , 51170 Köln , Germany
| | - Fan Yang
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR) , 51170 Köln , Germany
| | - Andreas Meyer
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR) , 51170 Köln , Germany
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18
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Abstract
The energetically favored icosahedral structure has been seen as the central figure for describing the local structure of simple liquids and glasses. Although regular icosahedral structures are rarely found, it is accepted that distorted icosahedral structures occur in simple liquids and glasses. However, which local structure dominates and why it is more frequent than the others remain unanswered questions. In this study, by using a recently developed structure descriptor, we show that docosahedral structures are the most favored not only in models of simple liquids and glasses but also in an experimental colloid glass. We also show that the the predominance of docosahedral structures is entropy-driven. Our findings represent a significant milestone towards comprehending mysterious phenomena such as supercooling, glass transition, and crystallization, where local structures play a key role.
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Affiliation(s)
- Kengo Nishio
- National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan
| | - Anh Khoa Augustin Lu
- National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan
| | - Takehide Miyazaki
- National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan
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Lee GW. Formation of Metastable Crystals from Supercooled, Supersaturated, and Supercompressed Liquids: Role of Crystal-Liquid Interfacial Free Energy. Crystals 2017; 7:326. [DOI: 10.3390/cryst7110326] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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20
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Lee S, Jo W, Cho YC, Lee HH, Lee GW. Solution electrostatic levitator for measuring surface properties and bulk structures of an extremely supersaturated solution drop above metastable zone width limit. Review of Scientific Instruments 2017; 88:055101. [PMID: 28571425 DOI: 10.1063/1.4982363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report on the first integrated apparatus for measuring surface and thermophysical properties and bulk structures of a highly supersaturated solution by combining electrostatic levitation with real-time laser/x-ray scattering. Even today, a proper characterization of supersaturated solutions far above their solubility limits is extremely challenging because heterogeneous nucleation sites such as container walls or impurities readily initiate crystallization before the measurements can be performed. In this work, we demonstrate simultaneous measurements of drying kinetics and surface tension of a potassium dihydrogen phosphate (KH2PO4) aqueous solution droplet and its bulk structural evolution beyond the metastable zone width limit. Our experimental finding shows that the noticeable changes of the surface properties are accompanied by polymerizations of hydrated monomer clusters. The novel electrostatic levitation apparatus presented here provides an effective means for studying a wide range of highly concentrated solutions and liquids in deep metastable states.
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Affiliation(s)
- Sooheyong Lee
- Center for Creative Convergence Research, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600, South Korea
| | - Wonhyuk Jo
- Center for Creative Convergence Research, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600, South Korea
| | - Yong Chan Cho
- Center for Creative Convergence Research, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600, South Korea
| | - Hyun Hwi Lee
- Pohang Light Source, Pohang Accelerator Laboratory (PAL), Pohang 790-784, South Korea
| | - Geun Woo Lee
- Center for Creative Convergence Research, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600, South Korea
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21
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Li L, Luo Q, Li R, Zhao H, Chapman KW, Chupas PJ, Wang L, Liu H. Polyamorphism in Yb-based metallic glass induced by pressure. Sci Rep 2017; 7:46762. [PMID: 28440339 DOI: 10.1038/srep46762] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 03/24/2017] [Indexed: 12/01/2022] Open
Abstract
The Yb62.5Zn15Mg17.5Cu5 metallic glass is investigated using synchrotron x-ray total scattering method up to 38.4 GPa. The polyamorphic transformation from low density to high density with a transition region between 14.1 and 25.2 GPa is observed, accompanying with a volume collapse reflected by a discontinuousness of isothermal bulk modulus. This collapse is caused by that distortional icosahedron short range order precedes to perfect icosahedron, which might link to Yb 4f electron delocalization upon compression, and match the result of in situ electrical resistance measurement under high pressure conditions. This discovery in Yb-based metallic glass, combined with the previous reports on other metallic glass systems, demonstrates that pressure induced polyamorphism is the general behavior for typical lanthanide based metallic glasses.
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Kelton KF. Kinetic and structural fragility-a correlation between structures and dynamics in metallic liquids and glasses. J Phys Condens Matter 2017; 29:023002. [PMID: 27841996 DOI: 10.1088/0953-8984/29/2/023002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The liquid phase remains poorly understood. In many cases, the densities of liquids and their crystallized solid phases are similar, but since they are amorphous they lack the spatial order of the solid. Their dynamical properties change remarkably over a very small temperature range. At high temperatures, near their melting temperature, liquids flow easily under shear. However, only a few hundred degrees lower flow effectively ceases, as the liquid transforms into a solid-like glass. This temperature-dependent dynamical behavior is frequently characterized by the concept of kinetic fragility (or, generally, simply fragility). Fragility is believed to be an important quantity in glass formation, making it of significant practical interest. The microscopic origin of fragility remains unclear, however, making it also of fundamental interest. It is widely (although not uniformly) believed that the dynamical behavior is linked to the atomic structure of the liquid, yet experimental studies show that although the viscosity changes by orders of magnitude with temperature, the structural change is barely perceptible. In this article the concept of fragility is discussed, building to a discussion of recent results in metallic glass-forming liquids that demonstrate the presumed connection between structural and dynamical changes. In particular, it becomes possible to define a structural fragility parameter that can be linked with the kinetic fragility.
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Affiliation(s)
- K F Kelton
- Department of Physics and the Institute of Materials Science and Engineering, Washington University, St. Louis, MO 63130, USA
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23
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Filipponi A, Di Cicco A, Iesari F, Trapananti A. The structure of liquid metals probed by XAS. EPJ Web Conf 2017. [DOI: 10.1051/epjconf/201715101001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Zhang Y, Ashcraft R, Mendelev M, Wang CZ, Kelton KF. Experimental and molecular dynamics simulation study of structure of liquid and amorphous Ni62Nb38 alloy. J Chem Phys 2016; 145:204505. [DOI: 10.1063/1.4968212] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Y. Zhang
- Division of Materials Sciences and Engineering, Ames Laboratory, Ames, Iowa 50011, USA
| | - R. Ashcraft
- Department of Physics and Institute of Materials Science & Engineering, Washington University, St. Louis, Missouri 63130, USA
| | - M.I. Mendelev
- Division of Materials Sciences and Engineering, Ames Laboratory, Ames, Iowa 50011, USA
| | - C. Z. Wang
- Division of Materials Sciences and Engineering, Ames Laboratory, Ames, Iowa 50011, USA
| | - K. F. Kelton
- Department of Physics and Institute of Materials Science & Engineering, Washington University, St. Louis, Missouri 63130, USA
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Jeon S, Kang DH, Lee YH, Lee S, Lee GW. Effect of atomic size on undercoolability of binary solid solution alloy liquids with Zr, Ti, and Hf using electrostatic levitation. J Chem Phys 2016; 145:174504. [PMID: 27825205 DOI: 10.1063/1.4966649] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigate the relationship between the excess volume and undercoolability of Zr-Ti and Zr-Hf alloy liquids by using electrostatic levitation. Unlike in the case of Zr-Hf alloy liquids in which sizes of the constituent atoms are matched, a remarkable increase of undercoolability and negative excess volumes are observed in Zr-Ti alloy liquids as a function of their compositional ratios. In this work, size mismatch entropies for the liquids were obtained by calculating their hard sphere diameters, number densities, and packing fractions. We also show that the size mismatch entropy, which arises from the differences in atomic sizes of the constituent elements, plays an important role in determining the stabilities of metallic liquids.
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Affiliation(s)
- S Jeon
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - D-H Kang
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - Y H Lee
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - S Lee
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - G W Lee
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
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26
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Lee B, Lee GW. A liquid-liquid transition can exist in monatomic transition metals with a positive melting slope. Sci Rep 2016; 6:35564. [PMID: 27762334 PMCID: PMC5071854 DOI: 10.1038/srep35564] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/03/2016] [Indexed: 01/26/2023] Open
Abstract
Liquid-liquid transitions under high pressure are found in many elemental materials, but the transitions are known to be associated with either sp-valent materials or f-valent rare-earth elements, in which the maximum or a negative slope in the melting line is readily suggestive of the transition. Here we find a liquid-liquid transition with a positive melting slope in transition metal Ti from structural, electronic, and thermodynamic studies using ab-initio molecular dynamics calculations, showing diffusion anomaly, but no density anomaly. The origin of the transition in liquid Ti is a pressure-induced increase of local structures containing very short bonds with directionality in electronic configurations. This behavior appears to be characteristic of the early transition metals. In contrast, the late transition metal liquid Ni does not show the L-L transition with pressure. This result suggests that the possibility of the L-L transition decreases from early to late transition metals as electronic structures of late transition metals barely have a Jahn-Teller effect and bond directionality. Our results generalize that a phase transition in disordered materials is found with any valence band regardless of the sign of the melting slope, but related to the symmetry of electronic structures of constituent elements.
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Affiliation(s)
- Byeongchan Lee
- Kyung Hee University, 1732 Deogyeong-daero, Yongin, Gyeonggi 17104, Republic of Korea
| | - Geun Woo Lee
- Korea Research Institute of Standards and Science, Daejon 34113, Republic of Korea.,University of Science and Technology, Daejon 34113, Republic of Korea
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27
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Urrutia Bañuelos E, Contreras Aburto C, Maldonado Arce A. A common neighbor analysis of crystallization kinetics and excess entropy of charged spherical colloids. J Chem Phys 2016; 144:094504. [DOI: 10.1063/1.4943001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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28
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29
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Abstract
A semi-ordered morphology with maze-like nano-patterns emerges due to the synergy effect and pinning effect of local icosahedral order during rapid cooling.
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Affiliation(s)
- Weikang Wu
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Leining Zhang
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Hongru Ren
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Kun Zhang
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Hui Li
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Yezeng He
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
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30
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Klatt MA, Torquato S. Characterization of maximally random jammed sphere packings: Voronoi correlation functions. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 90:052120. [PMID: 25493753 DOI: 10.1103/physreve.90.052120] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Indexed: 06/04/2023]
Abstract
We characterize the structure of maximally random jammed (MRJ) sphere packings by computing the Minkowski functionals (volume, surface area, and integrated mean curvature) of their associated Voronoi cells. The probability distribution functions of these functionals of Voronoi cells in MRJ sphere packings are qualitatively similar to those of an equilibrium hard-sphere liquid and partly even to the uncorrelated Poisson point process, implying that such local statistics are relatively structurally insensitive. This is not surprising because the Minkowski functionals of a single Voronoi cell incorporate only local information and are insensitive to global structural information. To improve upon this, we introduce descriptors that incorporate nonlocal information via the correlation functions of the Minkowski functionals of two cells at a given distance as well as certain cell-cell probability density functions. We evaluate these higher-order functions for our MRJ packings as well as equilibrium hard spheres and the Poisson point process. It is shown that these Minkowski correlation and density functions contain visibly more information than the corresponding standard pair-correlation functions. We find strong anticorrelations in the Voronoi volumes for the hyperuniform MRJ packings, consistent with previous findings for other pair correlations [A. Donev et al., Phys. Rev. Lett. 95, 090604 (2005)PRLTAO0031-900710.1103/PhysRevLett.95.090604], indicating that large-scale volume fluctuations are suppressed by accompanying large Voronoi cells with small cells, and vice versa. In contrast to the aforementioned local Voronoi statistics, the correlation functions of the Voronoi cells qualitatively distinguish the structure of MRJ sphere packings (prototypical glasses) from that of not only the Poisson point process but also the correlated equilibrium hard-sphere liquids. Moreover, while we did not find any perfect icosahedra (the locally densest possible structure in which a central sphere contacts 12 neighbors) in the MRJ packings, a preliminary Voronoi topology analysis indicates the presence of strongly distorted icosahedra.
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Affiliation(s)
- Michael A Klatt
- Department of Chemistry, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA and Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Institut für Theoretische Physik, Staudtstraße 7, 91058 Erlangen, Germany
| | - Salvatore Torquato
- Department of Chemistry, Department of Physics, Princeton Institute for the Science and Technology of Materials, and Program in Applied and Computational Mathematics, Princeton University, Princeton, New Jersey 08544, USA
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31
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Ding J, Xu M, Guan PF, Deng SW, Cheng YQ, Ma E. Temperature effects on atomic pair distribution functions of melts. J Chem Phys 2014; 140:064501. [DOI: 10.1063/1.4864106] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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32
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Gangopadhyay AK, Blodgett ME, Johnson ML, McKnight J, Wessels V, Vogt AJ, Mauro NA, Bendert JC, Soklaski R, Yang L, Kelton KF. Anomalous thermal contraction of the first coordination shell in metallic alloy liquids. J Chem Phys 2014; 140:044505. [PMID: 25669553 DOI: 10.1063/1.4861666] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A K Gangopadhyay
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - M E Blodgett
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - M L Johnson
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - J McKnight
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - V Wessels
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - A J Vogt
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - N A Mauro
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - J C Bendert
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - R Soklaski
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - L Yang
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
| | - K F Kelton
- Department of Physics, Washington University in St. Louis, Missouri 63130, USA
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33
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Lou H, Wang X, Cao Q, Zhang D, Zhang J, Hu T, Mao HK, Jiang JZ. Negative expansions of interatomic distances in metallic melts. Proc Natl Acad Sci U S A 2013; 110:10068-72. [PMID: 23733928 DOI: 10.1073/pnas.1307967110] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
When a material is heated, generally, it dilates. Here, we find a general trend that the average distance between a center atom and atoms in the first nearest-neighbor shell contracts for several metallic melts upon heating. Using synchrotron X-ray diffraction technique and molecular dynamics simulations, we elucidate that this anomaly is caused by the redistribution of polyhedral clusters affected by temperature. In metallic melts, the high-coordinated polyhedra are inclined to evolve into low-coordinated ones with increasing temperature. As the coordination number decreases, the average atomic distance between a center atom and atoms in the first shell of polyhedral clusters is reduced. This phenomenon is a ubiquitous feature for metallic melts consisting of various-sized polyhedra. This finding sheds light on the understanding of atomic structures and thermal behavior of disordered materials and will trigger more experimental and theoretical studies of liquids, amorphous alloys, glasses, and casting temperature effect on solidification process of crystalline materials.
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35
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Abstract
This work addresses the question on how the glass-forming ability (GFA) of a binary Pd-Ni metallic glass can be enhanced by the alloying effect of Pt. The structural features and slow dynamics of liquid and glassy states on both alloys are investigated by molecular dynamics simulations. Both alloys show typical features of glassy dynamics, namely, the non-Arrhenian behavior of diffusion and relaxation and the fractional Stokes-Einstein relation validity at low temperatures. On the basis of the analysis of the dynamical susceptibilities, we demonstrate that there is a strong influence of the alloying effect on the collective motion of the species, revealing that the GFA of the binary liquid increases with Pt alloying.
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Affiliation(s)
- Luis G V Gonçalves
- Departamento de Física, Universidade Federal de São Carlos, 13.565-905, São Carlos, São Paulo, Brazil
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37
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Abstract
The x-ray structure factors and densities for liquid aluminum from 1123 K to 1273 K have been measured using the beamline electrostatic levitator. Atomic structures as a function of temperature have been constructed from the diffraction data with reverse Monte Carlo simulations. An analysis of the local atomic structures in terms of the Honeycutt-Andersen indices indicates a high degree of icosahedral and distorted icosahedral order, a modest amount of body-centered cubic order, and marginal amounts of face-centered cubic and hexagonal close-packed order.
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Affiliation(s)
- N A Mauro
- Department of Physics, Center for Materials Innovation, Washington University, St. Louis, Missouri 63130-4899, USA.
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38
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Abstract
We have characterized the short-range order in the liquid and undercooled states of Au-Si alloy at the eutectic composition using molecular dynamics simulations. The interactions are described via a modified embedded-atom model refined to take into account the liquid properties. For the eutectic liquid, the local structure is characterized by a strong Au-Si affinity, namely a well-pronounced chemical short-range order which leads to the slowing down of the formation of icosahedral local motifs in the undercooled regime. Moreover we discuss the influence of this peculiar local structure on the dynamic and thermodynamic properties of the liquid phase and compare our results with available experimental data.
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Affiliation(s)
- N Jakse
- Laboratoire Sciences et Ingénierie, Matériaux et Procédés, UMR CNRS-INPG-UJF 5266, PHELMA-Grenoble-INP, BP 75, 38402 Saint Martin d'Hères Cedex, France
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Herlach DM, Klassen I, Wette P, Holland-Moritz D. Colloids as model systems for metals and alloys: a case study of crystallization. J Phys Condens Matter 2010; 22:153101. [PMID: 21389545 DOI: 10.1088/0953-8984/22/15/153101] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Metallic systems are widely used as materials in daily human life. Their properties depend very much on the production route. In order to improve the production process and even develop novel materials a detailed knowledge of all physical processes involved in crystallization is mandatory. Atomic systems like metals are characterized by very high relaxation rates, which make direct investigations of crystallization very difficult and in some cases impossible. In contrast, phase transitions in colloidal systems are very sluggish and colloidal suspensions are optically transparent. Therefore, colloidal systems are often discussed as model systems for metals. In the present work, we study the process of crystallization of charged colloidal systems from the very beginning. Charged colloids offer the advantage that the interaction potential can be systematically tuned by a variation of the particle number density and the salt concentration. We use light scattering and ultra-small angle x-ray scattering to investigate the formation of short-range order in the liquid state even far from equilibrium, crystal nucleation and crystal growth. The results are compared with those of equivalent studies on metallic systems. They are critically assessed as regards similarities and differences.
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Affiliation(s)
- Dieter M Herlach
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51147 Köln, Germany
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40
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Wojcik M, Lewandowski W, Matraszek J, Mieczkowski J, Borysiuk J, Pociecha D, Gorecka E. Liquid-Crystalline Phases Made of Gold Nanoparticles. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200901206] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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41
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Wojcik M, Lewandowski W, Matraszek J, Mieczkowski J, Borysiuk J, Pociecha D, Gorecka E. Liquid-Crystalline Phases Made of Gold Nanoparticles. Angew Chem Int Ed Engl 2009; 48:5167-9. [DOI: 10.1002/anie.200901206] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
There is continued interest in the problem of extracting structures from x-ray and neutron diffraction data on liquids and glasses. Traditional Fourier transform techniques, with their inherent weakness of possible systematic and truncation artefacts being introduced into the estimated distribution functions, are increasingly being complemented by computer simulation methods. These allow three-dimensional models of the scattering system to be built, at the correct atomic number density, which are consistent with both the diffraction data themselves and with other known or estimated constraints such minimum particle separations. Here the empirical potential structure refinement (EPSR) method is used to explore structure in supercooled liquid Ni, amorphous Ge and amorphous GeSe2, and to evaluate alternative versions of the radial distribution functions which are consistent with the diffraction data. In the case of liquid Ni, it is found that there is, based on the diffraction data, some uncertainty on the hardness and shape of the repulsive core of the interatomic pair potential, and this may influence the current debate about the existence of icosahedral order in this liquid. For amorphous Ge two distinct radial distribution functions are generated, both consistent with the diffraction data, one of which has strong tetrahedral local order with the other having a predominantly triangular local coordination. For amorphous GeSe2 it is found the SeSe and GeSe radial distribution functions can be determined well from the data, but the GeGe distribution is more uncertain, with the best fits implying both GeGe and SeSe homopolar bonds as originally proposed. The results are used to discuss the ambiguities inherent in the structural interpretation of diffraction data, even for one- and two-component systems.
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Affiliation(s)
- A K Soper
- ISIS Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxon OX11 0QX, UK
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45
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Abstract
Local structural models for supercooled liquid transition metals (Ti, Ni, and Zr) are proposed based on a reverse Monte Carlo analysis of high-energy x-ray diffraction data taken from the electrostatically levitated liquids. The resulting structures are characterized by their bond angle distributions, Honeycutt and Andersen indices [J. Phys. Chem. 91, 4950 (1987)], and bond orientational order parameters. All analyses suggest that an icosahedral short-range order is present in these supercooled liquids, but it is distorted in liquid Ti. These results are in agreement with the observed evolution of the high-q shoulder on the second peak in the structure factor S(q) and with an earlier analysis based on a local cluster model.
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Affiliation(s)
- T H Kim
- Department of Physics and the Center for Materials Innovation, Washington University, St. Louis, Missouri 63130, USA
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46
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Decremps F, Gauthier M, Ricquebourg F. Accurate equation of state of AlPdMn up to 35 GPa and pressure effect on the frozen-in phason strain. Phys Rev Lett 2006; 96:105501. [PMID: 16605755 DOI: 10.1103/physrevlett.96.105501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Indexed: 05/08/2023]
Abstract
Angle-dispersive monochromatic x-ray diffraction spectra from a perfect single-grain AlPdMn quasicrystal have been obtained under hydrostatic pressure in a diamond anvil cell up to 35 GPa. More than 50 Bragg peaks with sharpness comparable to that at ambient conditions were observed up to the maximum pressure, indexed and used to measure the hypercubic 6D lattice parameter, providing the most accurate determination of the equation of state in this pressure range to date. Within the instrumental resolution, the absence of broadening of the diffraction peaks indicates the absence of structural transition and/or unusual configurational entropy change expected from previous studies through pressure-induced amorphization or phason defects.
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Affiliation(s)
- F Decremps
- Physique des Milieux Denses, IMPMC, CNRS UMR 7590, Université Pierre et Marie Curie, 140 rue de Lourmel, 75015 Paris, France.
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47
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Abstract
We have investigated the structural and dynamic properties of liquid nickel by means of large-scale molecular-dynamics simulations, using an effective-pair potential derived from the second-order pseudopotential perturbation theory. The model of interactions is assessed on the single-atom as well as collective dynamic properties. The short-range order in the stable and undercooled liquids is also examined. We show that the present model potential gives a description of the local structure in both states in close agreement with first-principles molecular-dynamics simulations.
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Affiliation(s)
- Noël Jakse
- Laboratoire de Physique des Milieux Denses, Université de Metz, 1 Boulevard FD Arago, 57078 Metz Cedex 3, France.
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48
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Abstract
Measurements made in a laser heated diamond-anvil cell are reported that extend the melting curve of Xe to 80 GPa and 3350 K. The steep lowering of the melting slope (dT/dP) that occurs near 17 GPa and 2750 K results from the hybridization of the 5p-like valence and 5p-like conduction states with the formation of clusters in the liquid having icosahedral short-range order (ISRO).
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Affiliation(s)
- Marvin Ross
- Max Planck Institut für Chemie, 55020 Mainz, Germany
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49
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Jakse N, Le Bacq O, Pasturel A. Chemical and icosahedral short-range orders in liquid and undercooled Al80Mn20 and Al80Ni20 alloys: A first-principles-based approach. J Chem Phys 2005; 123:104508. [PMID: 16178611 DOI: 10.1063/1.1979495] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Atomic structures of stable liquid and undercooled liquid Al(80)Mn(20) and Al(80)Ni(20) alloys have been calculated by first-principles molecular-dynamics simulations. For both alloys, the local structure as defined by the Faber-Ziman pair-correlation functions is characterized by a strong Al-transition-metal affinity, which leads to a well-pronounced chemical short-range order which is more temperature dependent for Al(80)Mn(20) than for Al(80)Ni(20). In addition, a structural analysis using three-dimensional pair analysis techniques has been performed in details. More particularly, we find that the fivefold local symmetry around Mn atoms is predominant in both stable and undercooled Al(80)Mn(20) alloys and displays no significant variation with temperatures. On the contrary, in Al(80)Ni(20), a strong variation of the topological short-range order is observed since in the undercooled state, the local environment of Ni atoms is characterized by the predominance of the fivefold symmetry over the close-packed local symmetry which is opposed to what occurs in the stable liquid phase.
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Affiliation(s)
- N Jakse
- Laboratoire de Théorie des Milieux Denses, Université de Metz, France.
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