1
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Luo P, Zhai Y, Falus P, García Sakai V, Hartl M, Kofu M, Nakajima K, Faraone A, Z Y. Q-dependent collective relaxation dynamics of glass-forming liquid Ca 0.4K 0.6(NO 3) 1.4 investigated by wide-angle neutron spin-echo. Nat Commun 2022; 13:2092. [PMID: 35440658 PMCID: PMC9018732 DOI: 10.1038/s41467-022-29778-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 03/29/2022] [Indexed: 11/30/2022] Open
Abstract
The relaxation behavior of glass formers exhibits spatial heterogeneity and dramatically changes upon cooling towards the glass transition. However, the underlying mechanisms of the dynamics at different microscopic length scales are not fully understood. Employing the recently developed wide-angle neutron spin-echo spectroscopy technique, we measured the Q-dependent coherent intermediate scattering function of a prototypical ionic glass former Ca0.4K0.6(NO3)1.4, in the highly viscous liquid state. In contrast to the structure modulated dynamics for Q < 2.4 Å−1, i.e., at and below the structure factor main peak, for Q > 2.4 Å−1, beyond the first minimum above the structure factor main peak, the stretching exponent exhibits no temperature dependence and concomitantly the relaxation time shows smaller deviations from Arrhenius behavior. This finding indicates a change in the dominant relaxation mechanisms around a characteristic length of 2π/(2.4 Å−1) ≈ 2.6 Å, below which the relaxation process exhibits a temperature independent distribution and more Arrhenius-like behavior. Length scale dependence is important for understanding the collective relaxation dynamics in glass-forming liquids. Here, the authors find in liquid Ca0.4K0.6(NO3)1.4 a change in the dominant relaxation mechanisms around 2.6 Å, below which the relaxation process exhibits a temperature independent distribution and more Arrhenius-like behavior.
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Affiliation(s)
- Peng Luo
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Yanqin Zhai
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Peter Falus
- Institut Laue-Langevin (ILL), 38042, Grenoble, France
| | - Victoria García Sakai
- ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Science & Technology Facilities Council, Didcot, OX11 0QX, UK
| | - Monika Hartl
- European Spallation Source, SE-221 00, Lund, Sweden
| | - Maiko Kofu
- J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan
| | - Kenji Nakajima
- J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan
| | - Antonio Faraone
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, 20899-1070, USA.
| | - Y Z
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA. .,Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA. .,Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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2
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Hoffman DJ, Fayer MD. Discontinuity in Fast Dynamics at the Glass Transition of ortho-Terphenyl. J Phys Chem B 2017; 121:10417-10428. [PMID: 29039665 DOI: 10.1021/acs.jpcb.7b08301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dynamics of the molecular glass former ortho-terphenyl through the glass transition were observed with two-dimensional infrared vibrational spectroscopy measurements of spectral diffusion using the small probe molecule phenylselenocyanate. Although the slow diffusive motions were not visible on the experimental time scale, a picosecond-scale exponential relaxation was observed at temperatures from above to well below the glass transition temperature. The characteristic time scale has a smooth temperature dependence from the liquid into the glass phase, but the range of vibrational frequencies the probe samples displayed a discontinuity at the glass transition temperature. Complementary pump-probe experiments associate the observed motion with density fluctuations. The key features of the dynamics are reproduced with a simple corrugated well potential energy surface model. In addition, the temperature dependence of the homogeneous vibrational dephasing was found to have a T2 functional form, where T is the absolute temperature.
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Affiliation(s)
- David J Hoffman
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Michael D Fayer
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
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3
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Ngai KL, Capaccioli S, Prevosto D, Wang LM. Coupling of Caged Molecule Dynamics to JG β-Relaxation III: van der Waals Glasses. J Phys Chem B 2015; 119:12519-25. [PMID: 26340473 DOI: 10.1021/acs.jpcb.5b07294] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the first two papers separately on the polyalcohols and amorphous polymers of this series, we demonstrated that the fast dynamics observed in the glassy state at high frequencies above circa 1 GHz is the caged dynamics. We showed generally the intensity of the fast caged dynamics changes temperature dependence at a temperature THF nearly coincident with the secondary glass transition temperature Tgβ lower than the nominal glass transition temperature Tgα. The phenomenon is remarkable, since THF is determined from measurements of fast caged dynamics at short time scales typically in the ns to ps range, while Tgβ characterizes the secondary glass transition at which the Johari-Goldstein (JG) β-relaxation time τJG reaches a long time of ∼10(3) s, determined directly either by positronium annihilation lifetime spectroscopy, calorimetry, or low frequency dielectric and mechanical relaxation spectroscopy. The existence of the secondary glass transition originates from the dependence of τJG on density, previously proven by experiments performed at elevated pressure. The fact that THF ≈ Tgβ reflects the density dependence of the caged dynamics and coupling to the JG β-relaxation. The generality of the phenomenon and its theoretical rationalization implies the same should be observable in other classes of glass-formers. In this paper, III, we consider two archetypal small molecular van der Waals glass-formers, ortho-terphenyl and toluene. The experimental data show the same phenomenon. The present paper extends the generality of the phenomenon and explanation from the polyalcohols, a pharmaceutical, and many polymers to the small molecular van der Waals glass-formers.
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Affiliation(s)
- K L Ngai
- CNR-IPCF , Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy.,State Key Lab of Metastable Materials Science and Technology, Yanshan University , Qinhuangdao, Hebei 066004, China
| | - S Capaccioli
- CNR-IPCF , Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy.,Dipartimento di Fisica, Università di Pisa , Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy
| | - D Prevosto
- CNR-IPCF , Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy
| | - Li-Min Wang
- State Key Lab of Metastable Materials Science and Technology, Yanshan University , Qinhuangdao, Hebei 066004, China
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4
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Dynamics of supercooled liquids and glasses: comparison of experiments with theoretical predictions. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s002570050405] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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5
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Cummins HZ, Li G, Du W, Hwang YH, Shen GQ. Light Scattering Spectroscopy of Orthoterphenyl: Idealized and Extended Mode Coupling Analysis. ACTA ACUST UNITED AC 2013. [DOI: 10.1143/ptp.126.21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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6
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Wang LM, Mauro JC. An upper limit to kinetic fragility in glass-forming liquids. J Chem Phys 2011; 134:044522. [PMID: 21280763 DOI: 10.1063/1.3526942] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The kinetic fragility of a liquid is correlated to the magnitude of enthalpy hysteresis in various glass-forming materials during thermal cycling across the glass transition. While the lower bound of liquid fragility is well known, there has been little research into the possibility of an inherent upper limit to fragility. In this paper, we present a theoretical argument for the existence of a maximum fragility and show that the correlation between fragility and enthalpy hysteresis allows for an empirical evaluation of the upper limit of fragility. This upper limit occurs as the enthalpy hysteresis involved in thermal cycling about the glass transition approaches zero, leading to m(max)≈175. This result agrees remarkably well with our previous estimate. The dynamics of maximum fragility liquids are discussed, and a critical temperature of ∼1.5 T(g) (where T(g) is the glass transition temperature) is revealed where a transition from nonexponential to exponential structural relaxation occurs.
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Affiliation(s)
- Li-Min Wang
- State Key Laboratory of Metastable Materials Science and Technology and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004, China.
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7
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Magazù S, Migliardo F, Affouard F, Descamps M, Telling MTF. Study of the relaxational and vibrational dynamics of bioprotectant glass-forming mixtures by neutron scattering and molecular dynamics simulation. J Chem Phys 2010. [DOI: 10.1063/1.3407428] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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8
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Monaco G, Comez L, Fioretto D. Brillouin light scattering of a fragile glass former: O-terphenyl. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/13642819808204974] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- G. Monaco
- a Dipartimento di Fisica , Università dell'Aquila , I-67100 , L'Aquila , Italy
- b Istituto Nazionale per la Fisica della Materia , I-16152 , Genova , Italy
| | - L. Comez
- b Istituto Nazionale per la Fisica della Materia , I-16152 , Genova , Italy
- c Dipartimento di Fisica , Università di Perugia , I-06100 , Perugia , Italy
| | - D. Fioretto
- b Istituto Nazionale per la Fisica della Materia , I-16152 , Genova , Italy
- c Dipartimento di Fisica , Università di Perugia , I-06100 , Perugia , Italy
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9
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Langer JS. Anomalous diffusion in heterogeneous glass-forming liquids: temperature-dependent behavior. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:051115. [PMID: 19113103 DOI: 10.1103/physreve.78.051115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Indexed: 05/27/2023]
Abstract
In a preceding paper, Langer and Mukhopadhyay [Phys. Rev. E 77, 061505 (2008)] studied the diffusive motion of a tagged molecule in an heterogeneous glass-forming liquid at temperatures just above a glass transition. Among other features of this system, we postulated a relation between heterogeneity and stretched-exponential decay of correlations, and we also confirmed that systems of this kind generally exhibit non-Gaussian diffusion on intermediate length and time scales. Here I extend this analysis to higher temperatures approaching the point where the heterogeneities disappear and thermal activation barriers become small. I start by modifying the continuous-time random-walk theory proposed in Langer and Mukhopadhyay and supplement this analysis with an extension of the excitation-chain theory of glass dynamics. I also use a key result from the shear-transformation-zone theory of viscous deformation of amorphous materials. Elements of each of these theories are then used to interpret experimental data for orthoterphenyl, specifially, the diffusion and viscosity coefficients and neutron-scattering measurements of the self-intermediate scattering function. Reconciling the theory with these data sets provides insights into the crossover between super-Arrhenius and Arrhenius dynamics, length scales of spatial heterogeneities, violation of the Stokes-Einstein relation in glass-forming liquids, and the origin of stretched-exponential decay of correlations.
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Affiliation(s)
- J S Langer
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
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10
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Capaccioli S, Thayyil MS, Ngai KL. Critical Issues of Current Research on the Dynamics Leading to Glass Transition. J Phys Chem B 2008; 112:16035-49. [DOI: 10.1021/jp8057433] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- S. Capaccioli
- Dipartimento di Fisica, Università di Pisa and CNR-INFM, polylab, Largo Bruno Pontecorvo, 3, I-56127 Pisa, Italy
| | - M. Shahin Thayyil
- Dipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo, 3, I-56127 Pisa, Italy, and Department of Physics, University of Calicut, Kerala, India
| | - K. L. Ngai
- Naval Research Laboratory, Washington, DC 20375-5320
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11
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Petry W, Wuttke J. Quasielastic neutron scattering in glass forming viscous liquids. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/00411459508203945] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- W. Petry
- a Physikdepartement E13 , Technische Universität München , 85747 , Garching , GERMANY
| | - J. Wuttke
- a Physikdepartement E13 , Technische Universität München , 85747 , Garching , GERMANY
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12
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Criado A, Bermejo F, de Andres A, Martinez J. Microscopic dynamics of ortho-terphenyl in its polycrystalline and glassy forms. Mol Phys 2006. [DOI: 10.1080/00268979400100564] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- A. Criado
- a Instituto de Ciencia de Materiales, Consejo Superior de Investigaciones Cientificas , P.O. Box 1065, E-41080 , Sevilla , Spain
- b Departamento de Fisica de la Materia Condensada , Universidad de Sevilla , P.O. Box 1065, E-41080 , Sevilla , Spain
| | - F.J. Bermejo
- c Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas , Serrano 123, E-28006 , Madrid , Spain
| | - A. de Andres
- d Instituto de Ciencia de Materiales, C.S.I.C. , E-28049 , Madrid , Spain
- e Departamento de Fisica de Materiales C-IV , Universidad Autónoma de Madrid , E-28049 , Madrid , Spain
| | - J.L. Martinez
- d Instituto de Ciencia de Materiales, C.S.I.C. , E-28049 , Madrid , Spain
- e Departamento de Fisica de Materiales C-IV , Universidad Autónoma de Madrid , E-28049 , Madrid , Spain
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13
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Ghosh J, Faller R. A comparative molecular simulation study of the glass former ortho-terphenyl in bulk and freestanding films. J Chem Phys 2006; 125:44506. [PMID: 16942155 DOI: 10.1063/1.2210941] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We performed molecular dynamics simulations of the low-molecular weight organic glass former ortho-terphenyl in bulk and freestanding films. The main motivation is to provide molecular insight into the confinement effect without explicit interfaces. Based on earlier models of ortho-terphenyl we developed an atomistic model for bulk simulations. The model reproduces literature data both from simulations and experiments starting from specific volume and diffusivity to mean square displacement and radial distribution functions. After characterizing the bulk model we form freestanding films by the elongation and expansion method. These films give us the opportunity to study the dynamical heterogeneity near the glass transition through in-plane mobility and reorientation dynamics. We finally compare the model in bulk and under confinement. We found qualitatively a lower glass transition temperature for the freestanding film compared to the bulk.
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Affiliation(s)
- Jayeeta Ghosh
- Department of Chemical Engineering and Materials Science, University of California, Davis, California 95616, USA
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14
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Angelini R, Giura P, Monaco G, Ruocco G, Sette F. Relaxation dynamics in (HF)x(H2O)1-x solutions. J Chem Phys 2005; 123:34502. [PMID: 16080739 DOI: 10.1063/1.1949193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The high-frequency dynamics of (HF)(x)(H(2)O)(1-x) solutions has been investigated by inelastic x-ray scattering. The measurements have been performed as a function of the concentration in the range x = 0.20-0.73 at fixed temperature T = 283 K. The results have been compared with similar data in pure water (x = 0) and pure hydrogen fluoride (x = 1). A viscoelastic analysis of the data highlights the presence of a relaxation process characterized by a relaxation time and a strength directly related to the presence of a hydrogen-bond network in the system. The comparison with the data on water and hydrogen fluoride shows that the structural relaxation time continuously decreases at increasing concentration of hydrogen fluoride passing from the value for water to the one for hydrogen fluoride tau(alphaHF), which is three times smaller. This is the consequence of a gradual decreasing number of constraints of the hydrogen-bond networks in passing from one liquid to the other.
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Affiliation(s)
- R Angelini
- European Synchrotron Radiation Facility, B.P. 220, Grenoble, France.
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15
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Chong SH, Sciortino F. Structural relaxation in supercooled orthoterphenyl. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:051202. [PMID: 15244813 DOI: 10.1103/physreve.69.051202] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2003] [Indexed: 05/24/2023]
Abstract
We report molecular-dynamics simulation results performed for a model of molecular liquid orthoterphenyl in supercooled states, which we then compare with both experimental data and mode-coupling-theory (MCT) predictions, aiming at a better understanding of structural relaxation in orthoterphenyl. We pay special attention to the wave number dependence of the collective dynamics. It is shown that the simulation results for the model share many features with experimental data for real system, and that MCT captures the simulation results at the semiquantitative level except for intermediate wave numbers connected to the overall size of the molecule. Theoretical results at the intermediate wave number region are found to be improved by taking into account the spatial correlation of the molecule's geometrical center. This supports the idea that unusual dynamical properties at the intermediate wave numbers, reported previously in simulation studies for the model and discernible in coherent neutron-scattering experimental data, are basically due to the coupling of the rotational motion to the geometrical-center dynamics. However, there still remain qualitative as well as quantitative discrepancies between theoretical prediction and corresponding simulation results at the intermediate wave numbers, which call for further theoretical investigation.
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Affiliation(s)
- S-H Chong
- Dipartimento di Fisica and Istituto Nazionale per la Fisica della Materia, Center for Statistical Mechanics and Complexity, Università di Roma "La Sapienza," Piazzale Aldo Moro 2, I-00185, Roma, Italy
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16
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Cang H, Li J, Novikov VN, Fayer MD. Dynamical signature of two “ideal glass transitions” in nematic liquid crystals. J Chem Phys 2003. [DOI: 10.1063/1.1618215] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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17
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Cang H, Li J, Novikov VN, Fayer MD. Dynamics in supercooled liquids and in the isotropic phase of liquid crystals: A comparison. J Chem Phys 2003. [DOI: 10.1063/1.1568338] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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18
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Mossa S, La Nave E, Stanley HE, Donati C, Sciortino F, Tartaglia P. Dynamics and configurational entropy in the Lewis-Wahnström model for supercooled orthoterphenyl. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 65:041205. [PMID: 12005814 DOI: 10.1103/physreve.65.041205] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2001] [Indexed: 05/23/2023]
Abstract
We study thermodynamic and dynamic properties of a rigid model of the fragile glass-forming liquid orthoterphenyl. This model, introduced by Lewis and Wahnström in 1993, collapses each phenyl ring to a single interaction site; the intermolecular site-site interactions are described by the Lennard-Jones potential whose parameters have been selected to reproduce some bulk properties of the orthoterphenyl molecule. A system of N=343 molecules is considered in a wide range of densities and temperatures, reaching simulation times up to 1 micros. Such long trajectories allow us to equilibrate the system at temperatures below the mode coupling temperature T(c) at which the diffusion constant reaches values of order 10(-10) cm(2)/s and thereby to sample in a significant way the potential energy landscape in the entire temperature range. Working within the inherent structures thermodynamic formalism, we present results for the temperature and density dependence of the number, depth and shape of the basins of the potential energy surface. We evaluate the total entropy of the system by thermodynamic integration from the ideal-noninteracting-gas state and the vibrational entropy approximating the basin free energy with the free energy of 6N-3 harmonic oscillators. We evaluate the configurational part of the entropy as a difference between these two contributions. We study the connection between thermodynamical and dynamical properties of the system. We confirm that the temperature dependence of the configurational entropy and of the diffusion constant, as well as the inverse of the characteristic structural relaxation time, are strongly connected in supercooled states; we demonstrate that this connection is well represented by the Adam-Gibbs relation, stating a linear relation between logD and the quantity 1/TS(c). This relation is found to hold both above and below the critical temperature T(c)-as previously found in the case of silica-supporting the hypothesis that a connection exists between the number of basins and the connectivity properties of the potential energy surface.
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Affiliation(s)
- S Mossa
- Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215, USA
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19
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Brace DD, Gottke SD, Cang H, Fayer MD. Orientational dynamics of the glass forming liquid, dibutylphthalate: Time domain experiments and comparison to mode coupling theory. J Chem Phys 2002. [DOI: 10.1063/1.1427711] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Mossa S, Ruocco G, Sampoli M. Molecular dynamics simulation of the fragile glass former orthoterphenyl: a flexible molecule model. II. Collective dynamics. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 64:021511. [PMID: 11497593 DOI: 10.1103/physreve.64.021511] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2000] [Revised: 03/27/2001] [Indexed: 05/23/2023]
Abstract
We present a molecular dynamics study of the collective dynamics of a model for the fragile glass former orthoterphenyl. In this model, introduced by Mossa, Di Leonardo, Ruocco, and Sampoli [Phys. Rev. E 62, 612 (2000)], the intramolecular interaction among the three rigid phenyl rings is described by a set of force constants whose value has been fixed in order to obtain a realistic isolated molecule spectrum. The interaction between different molecules is described by a Lennard Jones site-site potential. We study the behavior of the coherent scattering functions F(t)(q,t), considering the density fluctuations of both molecular and phenyl-ring centers of mass; moreover we directly simulate the neutron scattering spectra taking into account both the contributions due to carbon and hydrogens atoms. We compare our results with the main predictions of the mode-coupling theory and with the available coherent neutron scattering experimental data.
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Affiliation(s)
- S Mossa
- Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215, USA
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21
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Kanaya T, Kaji K. Dynamics in the Glassy State and Near the Glass Transition of Amorphous Polymers as Studied by Neutron Scattering. POLYMER PHYSICS AND ENGINEERING 2001. [DOI: 10.1007/3-540-44484-x_2] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Wuttke J. Multiple-scattering effects on smooth neutron-scattering spectra. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 2000; 62:6531-6539. [PMID: 11101990 DOI: 10.1103/physreve.62.6531] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2000] [Indexed: 05/23/2023]
Abstract
Elastic and inelastic incoherent neutron-scattering experiments are simulated for simple models: a rigid solid (as used for normalization), a glass (with a smooth distribution of harmonic vibrations), and a viscous liquid (described by schematic mode-coupling equations). In cases where the input scattering law factorizes into a wave-number-dependent amplitude and a frequency-dependent spectral distribution, the latter is only weakly affected by multiple scattering, whereas the former is severely distorted.
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Affiliation(s)
- J Wuttke
- Physik-Department E13, Technische Universitat Munchen, 85747 Garching, Germany
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Hinze G, Brace DD, Gottke SD, Fayer MD. A detailed test of mode-coupling theory on all time scales: Time domain studies of structural relaxation in a supercooled liquid. J Chem Phys 2000. [DOI: 10.1063/1.1287595] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Wiedersich J, Surovtsev NV, Rössler E. A comprehensive light scattering study of the glass former toluene. J Chem Phys 2000. [DOI: 10.1063/1.481920] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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25
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Mossa S, Ruocco G, Sampoli M. Molecular dynamics simulation of the fragile glass-former orthoterphenyl: A flexible molecule model. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 2000; 62:612-630. [PMID: 11088498 DOI: 10.1103/physreve.62.612] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/1999] [Indexed: 05/23/2023]
Abstract
We present a realistic model of the fragile glass-former orthoterphenyl and the results of extensive molecular dynamics simulations in which we investigated its basic static and dynamic properties. In this model the internal molecular interactions between the three rigid phenyl rings are described by a set of force constants, including harmonic and anharmonic terms; the interactions among different molecules are described by Lennard-Jones site-site potentials. Self-diffusion properties are discussed in detail together with the temperature and momentum dependencies of the self-intermediate scattering function. The simulation data are compared with existing experimental results and with the main predictions of the mode-coupling theory.
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Affiliation(s)
- S Mossa
- Dipartimento di Fisica and INFM, Universita di L'Aquila, Via Vetoio, Coppito, L'Aquila, I-67100, Italy
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Hinze G, Brace DD, Gottke SD, Fayer MD. Orientational dynamics in supercooled liquids near T(c) and comparison with ideal mode-coupling theory. PHYSICAL REVIEW LETTERS 2000; 84:2437-2440. [PMID: 11018904 DOI: 10.1103/physrevlett.84.2437] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/1999] [Indexed: 05/23/2023]
Abstract
Orientational dynamics in supercooled salol and ortho-terphenyl were measured near their critical temperatures, T(c), with optical Kerr effect experiments spanning a very broad range of times. Above T(c), the decays are shown to be in excellent agreement with the master curve predicted by ideal mode-coupling theory when higher order terms are included. Between the critical decay and the von Schweidler power laws, the intermediate time range of the data can be modeled by a power law. This intermediate power law, located at 2<t<10 ps to 500 ps (depending on temperature), shows a significant temperature dependence with a power law exponent of approximately -1 below T(c).
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Affiliation(s)
- G Hinze
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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Kanaya T, Kawaguchi T, Kaji K. Local Dynamics of Some Bulk Polymers above Tg As Seen by Quasielastic Neutron Scattering. Macromolecules 1999. [DOI: 10.1021/ma970096q] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- T. Kanaya
- Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611, Japan
| | - T. Kawaguchi
- Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611, Japan
| | - K. Kaji
- Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611, Japan
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Gapiński J, Steffen W, Patkowski A, Sokolov AP, Kisliuk A, Buchenau U, Russina M, Mezei F, Schober H. Spectrum of fast dynamics in glass forming liquids: Does the “knee” exist? J Chem Phys 1999. [DOI: 10.1063/1.477966] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kanaya T, Zorn R, Tsukushi I, Murakami S, Kaji K, Richter D. Orientational effects on low-energy modes in amorphous poly(ethylene terephthalate) fiber. J Chem Phys 1998. [DOI: 10.1063/1.477728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hansen J, Kanaya T, Nishida K, Kaji K, Tanaka K, Yamaguchi A. Role of vibrational softening in fast dynamics of an amorphous polyimide far below Tg. J Chem Phys 1998. [DOI: 10.1063/1.476055] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ngai KL, Sokolov A, Steffen W. Correlations between boson peak strength and characteristics of local segmental relaxation in polymers. J Chem Phys 1997. [DOI: 10.1063/1.474889] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Koizumi S. Quasielastic neutron scattering study on rotational aromatic groups of a thermotropic copolyester (vectra). J Chem Phys 1997. [DOI: 10.1063/1.475157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Roland CM, Ngai KL. Short-time viscous and density relaxation in glycerol and ortho-terphenyl. J Chem Phys 1997. [DOI: 10.1063/1.473215] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Kanaya T, Kawaguchi T, Kaji K. Microscopic view of glass transition dynamics: A quasielastic neutron scattering study on trans‐1,4‐polychloroprene. J Chem Phys 1996. [DOI: 10.1063/1.472250] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ma J, Berg M. Application of mode-coupling theory to solvation dynamics. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:2786-2796. [PMID: 9965393 DOI: 10.1103/physreve.54.2786] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Roland CM, Ngai KL. Response to ‘‘Comment on ‘Short time dynamics of glass‐forming liquids’ ’’ [J. Chem. Phys. 104, 8169 (1996)]. J Chem Phys 1996. [DOI: 10.1063/1.471528] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kanaya T, Kawaguchi T, Kaji K. Fast process of amorphous polystyrene below and above the glass transition temperature Tg as studied by quasielastic neutron scattering. J Chem Phys 1996. [DOI: 10.1063/1.471037] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sokolov AP, Steffen W, Rössler E. High-temperature dynamics in glass-forming liquids. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 52:5105-5109. [PMID: 9964008 DOI: 10.1103/physreve.52.5105] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Wuttke J, Petry W, Coddens G, Fujara F. Fast dynamics of glass-forming glycerol. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 52:4026-4034. [PMID: 9963875 DOI: 10.1103/physreve.52.4026] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Cicerone MT, Ediger MD. Relaxation of spatially heterogeneous dynamic domains in supercooled ortho‐terphenyl. J Chem Phys 1995. [DOI: 10.1063/1.470551] [Citation(s) in RCA: 331] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Bartsch E, Fujara F, Legrand JF, Petry W, Sillescu H, Wuttke J. Dynamics in viscous orthoterphenyl: Results from coherent neutron scattering. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 52:738-745. [PMID: 9963475 DOI: 10.1103/physreve.52.738] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Lebon MJ, Dreyfus C, Li G, Aouadi A, Cummins HZ, Pick RM. Depolarized light-scattering study of molten zinc chloride. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 51:4537-4547. [PMID: 9963166 DOI: 10.1103/physreve.51.4537] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Lewis LJ, Wahnström G. Molecular-dynamics study of supercooled ortho-terphenyl. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1994; 50:3865-3877. [PMID: 9962441 DOI: 10.1103/physreve.50.3865] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Rössler E, Sokolov AP, Kisliuk A, Quitmann D. Low-frequency Raman scattering on different types of glass formers used to test predictions of mode-coupling theory. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:14967-14978. [PMID: 10010599 DOI: 10.1103/physrevb.49.14967] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Steffen W, Patkowski A, Gläser H, Meier G, Fischer EW. Depolarized-light-scattering study of orthoterphenyl and comparison with the mode-coupling model. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1994; 49:2992-3002. [PMID: 9961565 DOI: 10.1103/physreve.49.2992] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Roe R. Short time dynamics of polymer liquid and glass studied by molecular dynamics simulation. J Chem Phys 1994. [DOI: 10.1063/1.466588] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Gangasharan, Murthy SSN. Study of α‐, β‐, and γ‐relaxation processes in some supercooled liquids and supercooled plastic crystals. J Chem Phys 1993. [DOI: 10.1063/1.465470] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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