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Shirai K, Watanabe K, Momida H. First-principles study of the specific heat of glass at the glass transition with a case study on glycerol. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:375902. [PMID: 35785777 DOI: 10.1088/1361-648x/ac7e12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
The standard method to determine the transition temperature (Tg) of glasses is the jump in the specific heat,ΔCp. Despite its importance, standard theory for this jump is lacking. The difficulties include lack of proper treatment of the specific heat of liquids, hysteresis, and the timescale issue. The first part of this paper provides a non-empirical method for calculating the specific heat in the glass transition. The method consists of molecular dynamics (MD) simulations based on density-functional theory (DFT) and thermodynamics methods. Calculation of the total energy, which is the heart of DFT, is the most general method for obtaining specific heat for any state of matters. The influence of energy dissipation processes on specific heat is treated by adiabatic MD simulations. The problems of hysteresis and the timescale are alleviated by restricting the scope of calculations to equilibrium states only. The second part of this paper demonstrates the validity and usefulness of the methods by applying to the specific-heat jump of glycerol. By decomposingΔCpinto contributions of the structural, phonon, and thermal expansion energies, an appropriate interpretation for the specific-heat jump has been established: the major contribution toΔCpis the change in the structural energy. From this, a neat energy diagram about the glass transition is obtained. An outcome of this study is verification of the empirical relationship between the fragility and the specific-heat jump. These two quantities scale to the ratiok=Tg/ΔTg, whereΔTgis the width of the transition, through which the two quantities are interrelated.
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Affiliation(s)
- Koun Shirai
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Kota Watanabe
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Hiroyoshi Momida
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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2
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Mizuno Y, Zhao Y, Akiba H, Kohara S, Ohara K, Tucker MG, McDonnell MT, Yamamuro O. Intermolecular correlations of liquid and glassy CS2 studied by synchrotron radiation x-ray diffraction. J Chem Phys 2022; 156:034503. [DOI: 10.1063/5.0073210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yuki Mizuno
- Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
- Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Yuansheng Zhao
- Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Hiroshi Akiba
- Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Shinji Kohara
- National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Koji Ohara
- Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Matthew G. Tucker
- Oak Ridge National Laboratory (ORNL), 1 Bethel Valley Road, Oak Ridge, Tennessee 37830, USA
| | - Marshall T. McDonnell
- Oak Ridge National Laboratory (ORNL), 1 Bethel Valley Road, Oak Ridge, Tennessee 37830, USA
| | - Osamu Yamamuro
- Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
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3
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Nishiyama E, Yokota M, Tsukushi I. Configurational heat capacity of various polymers above the glass transition temperature. Polym J 2021. [DOI: 10.1038/s41428-021-00582-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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4
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Analysis of the configurational heat capacity of polystyrene and its monomer and oligomer above the glass transition temperature. Polym J 2021. [DOI: 10.1038/s41428-021-00554-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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5
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Ediger MD, Gruebele M, Lubchenko V, Wolynes PG. Glass Dynamics Deep in the Energy Landscape. J Phys Chem B 2021; 125:9052-9068. [PMID: 34357766 DOI: 10.1021/acs.jpcb.1c01739] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
When a liquid is cooled, progress down the energy landscape is arrested near the glass transition temperature Tg. In principle, lower energy states can be accessed by waiting for further equilibration, but the rough energy landscape of glasses quickly leads to kinetics on geologically slow time scales below Tg. Over the past decade, progress has been made probing deeper into the energy landscape via several techniques. By looking at bulk and surface diffusion, using layered deposition that promotes equilibration, imaging glass surfaces with faster dynamics below Tg, and optically exciting glasses, experiments have moved into a regime of ultrastable, low energy glasses that was difficult to access in the past. At the same time, both simulations and energy landscape theory based on a random first order transition (RFOT) have tackled systems that include surfaces, optical excitation, and interfacial dynamics. Here we review some of the recent experimental work, and how energy landscape theory illuminates glassy dynamics well below the glass transition temperature by making direct connections between configurational entropy, energy landscape barriers, and the resulting dynamics.
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Affiliation(s)
- Mark D Ediger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Martin Gruebele
- Department of Chemistry, Department of Physics, Center for Biophysics and Quantitative Biology, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, United States
| | - Vassiliy Lubchenko
- Departments of Chemistry and Physics, and the Center for Superconductivity, University of Houston, Houston, Texas 77204, United States
| | - Peter G Wolynes
- Departments of Chemistry, Physics and Astronomy, Biosciences, Materials Science and Nanoengineering, and the Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
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6
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Estimation of the configurational heat capacity of polyisobutylene, isobutane and 2,2,4-isomethylpentane above the glass transition temperature. Polym J 2021. [DOI: 10.1038/s41428-021-00503-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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7
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Xu WS, Douglas JF, Sun ZY. Polymer Glass Formation: Role of Activation Free Energy, Configurational Entropy, and Collective Motion. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02740] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Wen-Sheng Xu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Jack F. Douglas
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Zhao-Yan Sun
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
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8
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Parmar ADS, Ozawa M, Berthier L. Ultrastable Metallic Glasses In Silico. PHYSICAL REVIEW LETTERS 2020; 125:085505. [PMID: 32909772 DOI: 10.1103/physrevlett.125.085505] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
We develop a generic strategy and simple numerical models for multicomponent metallic glasses for which the swap Monte Carlo algorithm can produce highly stable equilibrium configurations equivalent to experimental systems cooled more than 10^{7} times slower than in conventional simulations. This paves the way for a deeper understanding of the thermodynamic, dynamic, and mechanical properties of metallic glasses. As first applications, we considerably extend configurational entropy measurements down to the experimental glass temperature, and demonstrate a qualitative change of the mechanical response of metallic glasses of increasing stability toward brittleness.
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Affiliation(s)
- Anshul D S Parmar
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, 34095 Montpellier, France
| | - Misaki Ozawa
- Laboratoire de Physique Statistique, École Normale Supérieure, CNRS, PSL Research University, Sorbonne Université, 75005 Paris, France
| | - Ludovic Berthier
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, 34095 Montpellier, France
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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9
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Mizuguchi T, Tatsumi S, Fujiwara S. Icosahedral order in liquid and glassy phases of cyclohexane. MOLECULAR SIMULATION 2020. [DOI: 10.1080/08927022.2020.1757092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Tomoko Mizuguchi
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Kyoto, Japan
| | - Soichi Tatsumi
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Kyoto, Japan
| | - Susumu Fujiwara
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Kyoto, Japan
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10
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Ozawa M, Scalliet C, Ninarello A, Berthier L. Does the Adam-Gibbs relation hold in simulated supercooled liquids? J Chem Phys 2019; 151:084504. [DOI: 10.1063/1.5113477] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- Misaki Ozawa
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
| | - Camille Scalliet
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
| | | | - Ludovic Berthier
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
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11
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Beasley MS, Bishop C, Kasting BJ, Ediger MD. Vapor-Deposited Ethylbenzene Glasses Approach "Ideal Glass" Density. J Phys Chem Lett 2019; 10:4069-4075. [PMID: 31269793 DOI: 10.1021/acs.jpclett.9b01508] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Spectroscopic ellipsometry was used to characterize vapor-deposited glasses of ethylbenzene (Tg = 115.7 K). For this system, previous calorimetric experiments have established that a transition to the ideal glass state is expected to occur near 101 K (the Kauzmann temperature, TK) if the low-temperature supercooled liquid has the properties expected based upon extrapolation from above Tg. Ethylbenzene glasses were vapor-deposited at substrate temperatures between 100 (∼0.86 Tg) and 116 K (∼Tg), using deposition rates of 0.02-2.1 nm/s. Down to 103 K, glasses prepared in the limit of low deposition rate have densities consistent with the extrapolated supercooled liquid. The highest density glass is within 0.15% of the density expected for the ideal glass. These results support the hypothesis that the extrapolated properties of supercooled ethylbenzene are correct to within just a few Kelvin of TK, consistent with the existence of a phase transition to an ideal glass state at TK.
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Affiliation(s)
- M S Beasley
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - C Bishop
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - B J Kasting
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - M D Ediger
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
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12
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Zhang H, Wang X, Chremos A, Douglas JF. Superionic UO2: A model anharmonic crystalline material. J Chem Phys 2019; 150:174506. [DOI: 10.1063/1.5091042] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Hao Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Xinyi Wang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Alexandros Chremos
- Material Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Jack F. Douglas
- Material Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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13
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Berthier L, Ozawa M, Scalliet C. Configurational entropy of glass-forming liquids. J Chem Phys 2019; 150:160902. [PMID: 31042883 DOI: 10.1063/1.5091961] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The configurational entropy is one of the most important thermodynamic quantities characterizing supercooled liquids approaching the glass transition. Despite decades of experimental, theoretical, and computational investigation, a widely accepted definition of the configurational entropy is missing, its quantitative characterization remains fraught with difficulties, misconceptions, and paradoxes, and its physical relevance is vividly debated. Motivated by recent computational progress, we offer a pedagogical perspective on the configurational entropy in glass-forming liquids. We first explain why the configurational entropy has become a key quantity to describe glassy materials, from early empirical observations to modern theoretical treatments. We explain why practical measurements necessarily require approximations that make its physical interpretation delicate. We then demonstrate that computer simulations have become an invaluable tool to obtain precise, nonambiguous, and experimentally relevant measurements of the configurational entropy. We describe a panel of available computational tools, offering for each method a critical discussion. This perspective should be useful to both experimentalists and theoreticians interested in glassy materials and complex systems.
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Affiliation(s)
- Ludovic Berthier
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
| | - Misaki Ozawa
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
| | - Camille Scalliet
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier, France
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14
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Berthier L, Charbonneau P, Ninarello A, Ozawa M, Yaida S. Zero-temperature glass transition in two dimensions. Nat Commun 2019; 10:1508. [PMID: 30944330 PMCID: PMC6447585 DOI: 10.1038/s41467-019-09512-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/10/2019] [Indexed: 12/03/2022] Open
Abstract
Liquids cooled towards the glass transition temperature transform into amorphous solids that have a wide range of applications. While the nature of this transformation is understood rigorously in the mean-field limit of infinite spatial dimensions, the problem remains wide open in physical dimensions. Nontrivial finite-dimensional fluctuations are hard to control analytically, and experiments fail to provide conclusive evidence regarding the nature of the glass transition. Here, we develop Monte Carlo methods for two-dimensional glass-forming liquids that allow us to access equilibrium states at sufficiently low temperatures to directly probe the glass transition in a regime inaccessible to experiments. We find that the liquid state terminates at a thermodynamic glass transition which occurs at zero temperature and is associated with an entropy crisis and a diverging static correlation length. Our results thus demonstrate that a thermodynamic glass transition can occur in finite dimensional glass-formers.
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Affiliation(s)
- Ludovic Berthier
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, F-34095, Montpellier, France.
| | - Patrick Charbonneau
- Department of Chemistry, Duke University, Durham, NC, 27708, USA
- Department of Physics, Duke University, Durham, NC, 27708, USA
| | - Andrea Ninarello
- CNR-ISC, UOS Sapienza, Piazzale A. Moro 2, IT-00185, Roma, Italy
| | - Misaki Ozawa
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, F-34095, Montpellier, France
| | - Sho Yaida
- Facebook AI Research, Facebook Inc., Menlo Park, CA, 94025, USA
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15
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Affiliation(s)
- G. P. Johari
- Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario L8S 4L7, Canada
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16
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Ozawa M, Parisi G, Berthier L. Configurational entropy of polydisperse supercooled liquids. J Chem Phys 2018; 149:154501. [DOI: 10.1063/1.5040975] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- Misaki Ozawa
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, Montpellier, France
| | - Giorgio Parisi
- Dipartimento di Fisica, Università degli studi di Roma La Sapienza, Nanotec-CNR, UOS Rome, INFN-Sezione di Roma 1, Piazzale A. Moro 2, 00185 Rome, Italy
| | - Ludovic Berthier
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, Montpellier, France
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17
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Royall CP, Turci F, Tatsumi S, Russo J, Robinson J. The race to the bottom: approaching the ideal glass? JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:363001. [PMID: 29972145 DOI: 10.1088/1361-648x/aad10a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Key to resolving the scientific challenge of the glass transition is to understand the origin of the massive increase in viscosity of liquids cooled below their melting temperature (avoiding crystallisation). A number of competing and often mutually exclusive theoretical approaches have been advanced to describe this phenomenon. Some posit a bona fide thermodynamic phase to an 'ideal glass', an amorphous state with exceptionally low entropy. Other approaches are built around the concept of the glass transition as a primarily dynamic phenomenon. These fundamentally different interpretations give equally good descriptions of the data available, so it is hard to determine which-if any-is correct. Recently however this situation has begun to change. A consensus has emerged that one powerful means to resolve this longstanding question is to approach the putative thermodynamic transition sufficiently closely, and a number of techniques have emerged to meet this challenge. Here we review the results of some of these new techniques and discuss the implications for the existence-or otherwise-of the thermodynamic transition to an ideal glass.
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Affiliation(s)
- C Patrick Royall
- HH Wills Physics Laboratory, Tyndall Avenue, Bristol, BS8 1TL, United Kingdom. School of Chemistry, University of Bristol, Cantock Close, Bristol, BS8 1TS, United Kingdom. Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol, BS8 1FD, United Kingdom
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18
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Matyushov DV. Configurational entropy of polar glass formers and the effect of electric field on glass transition. J Chem Phys 2016; 145:034504. [DOI: 10.1063/1.4959035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Dmitry V. Matyushov
- Department of Physics and School of Molecular Sciences, Arizona State University, P.O. Box 871504, Tempe, Arizona 85287, USA
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19
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Hyeon-Deuk K, Ando K. Distinct structural and dynamical difference between supercooled and normal liquids of hydrogen molecules. Phys Chem Chem Phys 2016; 18:2314-8. [PMID: 26750610 DOI: 10.1039/c5cp06615h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Supercooled hydrogen liquid as well as superfluid have continued to elude experimental observation due to rapid crystallization. We computationally realized and investigated supercooled hydrogen liquid by a recently developed non-empirical real-time molecular dynamics method, which describes non-spherical hydrogen molecules with the nuclear quantum effects. We demonstrated that the hydrogen supercooled liquid is not a simply cooled liquid but rather exhibits intrinsic structural and dynamical characters including a precursor of tunneling and superfluidity which neither normal hydrogen liquid nor solid possesses. All of the insights provide a milestone for planning experiments of metastable hydrogen systems like glassy and superfluid states and for identifying various unknown hydrogen phases.
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Affiliation(s)
- Kim Hyeon-Deuk
- Department of Chemistry, Kyoto University, Kyoto 606-8502, Japan. and Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Koji Ando
- Department of Chemistry, Kyoto University, Kyoto 606-8502, Japan.
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20
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Ionic liquids and their bases: Striking differences in the dynamic heterogeneity near the glass transition. Sci Rep 2015; 5:16876. [PMID: 26582136 PMCID: PMC4652270 DOI: 10.1038/srep16876] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 10/21/2015] [Indexed: 11/08/2022] Open
Abstract
Ionic liquids (ILs) constitute an active field of research due to their important applications. A challenge for these investigations is to explore properties of ILs near the glass transition temperature Tg, which still require our better understanding. To shed a new light on the issues, we measured ILs and their base counterparts using the temperature modulated calorimetry. We performed a comparative analysis of the dynamic heterogeneity at Tg for bases and their salts with a simple monoatomic anion (Cl(-)). Each pair of ionic and non-ionic liquids is characterized by nearly the same chemical structure but their intermolecular interactions are completely different. We found that the size of the dynamic heterogeneity of ILs near Tg is considerably smaller than that established for their dipolar counterparts. Further results obtained for several other ILs near Tg additionally strengthen the conclusion about the relatively small size of the dynamic heterogeneity of molecular systems dominated by electrostatic interactions. Our finding opens up new perspectives on designing different material properties depending on intermolecular interaction types.
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21
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Nagoe A, Oguni M, Fujimori H. Low-temperature heat capacities of confined liquid benzene, implying the behavior of ordinary bulk liquids. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:455103. [PMID: 26490197 DOI: 10.1088/0953-8984/27/45/455103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Isobaric heat capacities C p of benzene confined in silica MCM-41 mesopores with average diameters equal to and smaller than 2.9 nm were measured by precise adiabatic calorimetry. The confined benzene samples revealed no thermal anomaly due to crystallization/fusion and vitrified at low temperatures. The C p curves displayed a hump and a considerably quick decrease on the low-temperature side of the hump as the pore diameter increased. The enthalpy-relaxation effects observed on intermittent heating showed that the anomaly of the C p hump and quick decrease is not assigned to a glass transition. The bend in the temperature dependence of density reported previously was interpreted as corresponding to the quick decrease in C p . We concluded that the anomalous C p and density behaviors originated from the ordering/excitation in the configurational state, close to the ground state, of confined molecular aggregate and proposed a scenario that explains the general C p curves of ordinary bulk supercooled liquids in equilibrium at low temperatures below the glass-transition temperatures.
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Affiliation(s)
- A Nagoe
- Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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22
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Ishii K, Nakayama H. Structural relaxation of vapor-deposited molecular glasses and supercooled liquids. Phys Chem Chem Phys 2014; 16:12073-92. [DOI: 10.1039/c4cp00458b] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The properties of vapor-deposited molecular glasses largely depend on deposition conditions, and stable and/or dense glasses are formed with several compounds.
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Affiliation(s)
- Kikujiro Ishii
- Department of Chemistry
- Gakushuin University
- Tokyo 171-8588, Japan
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23
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Benassi P, Nardone M, Giugni A. Ultraviolet and visible Brillouin scattering study of viscous relaxation in 3-methylpentane down to the glass transition. J Chem Phys 2012; 137:094504. [PMID: 22957578 DOI: 10.1063/1.4748354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Brillouin light scattering spectra from transverse and longitudinal acoustic waves in liquid and supercooled 3-methylpentane have been collected from room temperature down to 80 K, just above the glass transition. Spectra at different wave vectors have been obtained using 532 nm and 266 nm excitation. We found evidence of a shear relaxation with a characteristic time of 100 s at the glass transition which only partly accounts for the relaxation observed in the propagation and attenuation of the longitudinal modes. The inclusion of a relaxing bulk viscosity contribution with a relaxation time of the order of 10(2) ns at the glass transition is found to adequately reproduce the experimental data including transient grating data at a much lower frequency. A consistent picture of relaxed shear and bulk moduli as a function of temperature is derived. These two quantities are found to be related by a linear relation suggesting that a Cauchy-like relation holds also above the glass transition.
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Affiliation(s)
- P Benassi
- Dipartimento di Fisica and CNISM-CNR, Università de L'Aquila, via Vetoio, 67100 Coppito, Italy
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