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Cassidy A, Jørgensen MRV, Glavic A, Lauter V, Plekan O, Field D. Low temperature aging in a molecular glass: the case of cis-methyl formate. Phys Chem Chem Phys 2021; 23:15719-15726. [PMID: 34279530 DOI: 10.1039/d1cp01332g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Glassy films of cis-methyl formate show spontaneous dipole orientation on deposition from the vacuum, the so-called 'spontelectric effect', creating surface potentials and electric fields within the films. We follow the decay of these fields, and their accompanying dipole orientation, on the hours timescale at deposition temperatures between 40 K and 55 K. Our data trace the low temperature 'secondary decay' mechanism, at tens of degrees below the glass transition temperature of 90 K. We show that secondary decay is due to molecular rotation, with associated activation energies lying between 0.1 and 0.2 eV. Diffusion is absent, as established from published neutron reflectivity data. Using an analytical model for the spontelectric effect, data are placed on a quantitative footing, showing that angular motion in excess of 50° reproduces the observed values of activation energies. Exploitation of the spontelectric effect is new in the study of glass aging and is shown here to give insight into the elusive processes which take place far from the molecular glass transition temperature.
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Affiliation(s)
- Andrew Cassidy
- Center for Interstellar Catalysis and Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, Aarhus C, Denmark.
| | - Mads R V Jørgensen
- Center of Materials Crystallography, iNano & Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus C, Denmark and MAX IV Laboratory, Lund University, Fotongatan 2, Lund, Sweden
| | - Artur Glavic
- Laboratory for Neutron and Muon Instrumentation, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Valeria Lauter
- Neutron Scattering Division, Oak Ridge National Lab, Oak Ridge, TN 37831, USA
| | - Oksana Plekan
- Sincrotrone Trieste S.C.P.A., Area Science Park, Strada Statale 14, km 163.5, I-34149 Basovizza, Trieste, Italy
| | - David Field
- Center for Interstellar Catalysis and Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, Aarhus C, Denmark.
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2
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Raegen AN, Zhou Q, Forrest JA. Anisotropy and anharmonicity in polystyrene stable glass. J Chem Phys 2020; 153:214508. [PMID: 33291898 DOI: 10.1063/5.0032153] [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
We have used ellipsometry to characterize the anisotropy in stable polymer glasses prepared by physical vapor deposition. These measurements reveal birefringence values (as measured by the magnitude of in-plane vs out-of-plane refractive index) less than 0.002 in vapor-deposited polystyrenes with N from 6 to 12 and with fictive temperatures between 10 K and 35 K below the Tg values. We have measured the thermal expansivity of these stable glasses and compared to ordinary rejuvenated glass. The thermal expansivity of the stable glasses is less than that of ordinary glass with a difference that increases as the fictive temperature Tf decreases.
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Affiliation(s)
- Adam N Raegen
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Qi Zhou
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - James A Forrest
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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3
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Aldiyarov A, Sokolov DY, Nurmukan AY, Ramos MA. Refractive Index at Low Temperature of Tetrachloromethane and Tetrafluoroethane Cryovacuum Condensates. ACS OMEGA 2020; 5:11671-11676. [PMID: 32478257 PMCID: PMC7254780 DOI: 10.1021/acsomega.0c00969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/29/2020] [Indexed: 06/11/2023]
Abstract
We present low-temperature measurements of the refractive index of cryofilms of tetrachloromethane and 1,1,1,2-tetrafluoroethane at different condensation and measurement temperatures between 16 and 130 K. Using cryovacuum condensation, we have been able to obtain thin films in an amorphous state for both substances despite them being very bad glass formers. Then, we have studied the evolution of the refractive index with an increasing temperature, including by transitions to ordered or partially disordered crystalline states.
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Affiliation(s)
- Abdurakhman
U. Aldiyarov
- Al-Farabi
Kazakh National University Institute of Experimental and Theoretical
Physics, Physico-Technical
Faculty, al-Farabi Ave
71, Almaty 050040, Kazakhstan
| | - Dmitriy Yurievich Sokolov
- Al-Farabi
Kazakh National University Institute of Experimental and Theoretical
Physics, Physico-Technical
Faculty, al-Farabi Ave
71, Almaty 050040, Kazakhstan
| | - Assel Yerzhumayevna Nurmukan
- Al-Farabi
Kazakh National University Institute of Experimental and Theoretical
Physics, Physico-Technical
Faculty, al-Farabi Ave
71, Almaty 050040, Kazakhstan
| | - Miguel Angel Ramos
- Fisica
de la Materia Condensada, Francisco Tomas y Valiente, Universidad Autonoma de Madrid, 7 Facultad de Ciencias Modulo 03, Madrid E-28049, Spain
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4
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Cubeta US, Sadtchenko V. Glass softening kinetics in the limit of high heating rates. J Chem Phys 2019; 150:094508. [DOI: 10.1063/1.5046304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ulyana S. Cubeta
- Chemistry Department, The George Washington University, Washington, District of Columbia 20052, USA
| | - Vlad Sadtchenko
- Chemistry Department, The George Washington University, Washington, District of Columbia 20052, USA
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5
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Vila-Costa A, Ràfols-Ribé J, Gonzalez-Silveira M, Lopeandía A, Tamarit JL, Rodríguez-Viejo J. Multiple glass transitions in vapor-deposited orientational glasses of the most fragile plastic crystal Freon 113. Phys Chem Chem Phys 2019; 21:10436-10441. [DOI: 10.1039/c9cp00976k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Stable glass formation for both structural glass and as-deposited glassy crystal at deposition temperatures below Tg.
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Affiliation(s)
- A. Vila-Costa
- Grup de Nanomaterials i Microsistemes
- Departament de Física
- Universitat Autònoma de Barcelona
- 08193 Bellaterra
- Spain
| | - J. Ràfols-Ribé
- Grup de Nanomaterials i Microsistemes
- Departament de Física
- Universitat Autònoma de Barcelona
- 08193 Bellaterra
- Spain
| | - M. Gonzalez-Silveira
- Grup de Nanomaterials i Microsistemes
- Departament de Física
- Universitat Autònoma de Barcelona
- 08193 Bellaterra
- Spain
| | - A. Lopeandía
- Grup de Nanomaterials i Microsistemes
- Departament de Física
- Universitat Autònoma de Barcelona
- 08193 Bellaterra
- Spain
| | - J. Ll. Tamarit
- Grup de Caracterització de Materials
- Departament de Física and Barcelona Research Center in Multiscale Science and Engineering
- Universitat Politècnica de Catalunya
- EEBE
- 08019 Barcelona
| | - J. Rodríguez-Viejo
- Grup de Nanomaterials i Microsistemes
- Departament de Física
- Universitat Autònoma de Barcelona
- 08193 Bellaterra
- Spain
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6
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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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7
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Beasley MS, Tylinski M, Chua YZ, Schick C, Ediger MD. Glasses of three alkyl phosphates show a range of kinetic stabilities when prepared by physical vapor deposition. J Chem Phys 2018; 148:174503. [DOI: 10.1063/1.5026505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M. S. Beasley
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M. Tylinski
- Department of Chemistry, Widener University, Chester, Pennsylvania 19013, USA
| | - Y. Z. Chua
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Center CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - C. Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Center CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - M. D. Ediger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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8
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Luo S, Chen Y, Sha Y, Xue G, Zhuravlev E, Schick C, Wang X, Zhou D, Li L. Molecular weight and interfacial effect on the kinetic stabilization of ultrathin polystyrene films. POLYMER 2018. [DOI: 10.1016/j.polymer.2017.11.075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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9
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Affiliation(s)
- M. D. Ediger
- Department of Chemistry, University of Wisconsin-Madison,
1101 University Avenue, Madison, Wisconsin 53706, USA
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10
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Antony L, Jackson NE, Lyubimov I, Vishwanath V, Ediger MD, de Pablo JJ. Influence of Vapor Deposition on Structural and Charge Transport Properties of Ethylbenzene Films. ACS CENTRAL SCIENCE 2017; 3:415-424. [PMID: 28573203 PMCID: PMC5445540 DOI: 10.1021/acscentsci.7b00041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Indexed: 06/07/2023]
Abstract
Organic glass films formed by physical vapor deposition exhibit enhanced stability relative to those formed by conventional liquid cooling and aging techniques. Recently, experimental and computational evidence has emerged indicating that the average molecular orientation can be tuned by controlling the substrate temperature at which these "stable glasses" are grown. In this work, we present a comprehensive all-atom simulation study of ethylbenzene, a canonical stable-glass former, using a computational film formation procedure that closely mimics the vapor deposition process. Atomistic studies of experimentally formed vapor-deposited glasses have not been performed before, and this study therefore begins by verifying that the model and method utilized here reproduces key structural features observed experimentally. Having established agreement between several simulated and experimental macroscopic observables, simulations are used to examine the substrate temperature dependence of molecular orientation. The results indicate that ethylbenzene glasses are anisotropic, depending upon substrate temperature, and that this dependence can be understood from the orientation present at the surface of the equilibrium liquid. By treating ethylbenzene as a simple model for molecular semiconducting materials, a quantum-chemical analysis is then used to show that the vapor-deposited glasses exhibit decreased energetic disorder and increased magnitude of the mean-squared transfer integral relative to isotropic, liquid-cooled films, an effect that is attributed to the anisotropic ordering of the molecular film. These results suggest a novel structure-function simulation strategy capable of tuning the electronic properties of organic semiconducting glasses prior to experimental deposition, which could have considerable potential for organic electronic materials design.
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Affiliation(s)
- Lucas
W. Antony
- Institute
for Molecular Engineering, University of
Chicago, Chicago, Illinois 60637, United States
| | - Nicholas E. Jackson
- Institute
for Molecular Engineering, University of
Chicago, Chicago, Illinois 60637, United States
- The
Institute for Molecular Engineering, Argonne
National Laboratory, Lemont, Illinois 06349, United States
| | - Ivan Lyubimov
- Institute
for Molecular Engineering, University of
Chicago, Chicago, Illinois 60637, United States
| | - Venkatram Vishwanath
- Advanced
Leadership Computing Facility, Argonne National
Laboratory, Lemont, Illinois 06349, United States
| | - Mark D. Ediger
- Department
of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Juan J. de Pablo
- Institute
for Molecular Engineering, University of
Chicago, Chicago, Illinois 60637, United States
- The
Institute for Molecular Engineering, Argonne
National Laboratory, Lemont, Illinois 06349, United States
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11
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Ràfols-Ribé J, Gonzalez-Silveira M, Rodríguez-Tinoco C, Rodríguez-Viejo J. The role of thermodynamic stability in the characteristics of the devitrification front of vapour-deposited glasses of toluene. Phys Chem Chem Phys 2017; 19:11089-11097. [DOI: 10.1039/c7cp00741h] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Glass stability and molecular shape affect the transformation mechanism of vapour deposited glasses.
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Affiliation(s)
- Joan Ràfols-Ribé
- Grup de Nanomaterials i Microsistemes
- Physics Department
- Universtitat Autònoma de Barcelona
- 08193 Bellaterra
- Spain
| | - Marta Gonzalez-Silveira
- Grup de Nanomaterials i Microsistemes
- Physics Department
- Universtitat Autònoma de Barcelona
- 08193 Bellaterra
- Spain
| | - Cristian Rodríguez-Tinoco
- Grup de Nanomaterials i Microsistemes
- Physics Department
- Universtitat Autònoma de Barcelona
- 08193 Bellaterra
- Spain
| | - Javier Rodríguez-Viejo
- Grup de Nanomaterials i Microsistemes
- Physics Department
- Universtitat Autònoma de Barcelona
- 08193 Bellaterra
- Spain
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12
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Andersson O, Johari GP. Sub-T g features of glasses formed by cooling glycerol under pressure - Additional incompatibility of vibrational with configurational states in the depressurized, high density glass. J Chem Phys 2016; 145:204506. [PMID: 27908124 DOI: 10.1063/1.4968019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The vibrational state of a glass is naturally incompatible with its configurational state, which makes the glass structurally unstable. When a glass is kept at constant temperature, both the vibrational and configurational states of a glass change with time until it becomes metastable (equilibrium) liquid and the two states become compatible. The process, known as structural relaxation, occurs at a progressively higher rate during heating, and the properties of a glass change accordingly. We add to this incompatibility by depressurizing a glass that had been formed by cooling a liquid under a high pressure, p, and then investigate the effects of the added incompatibility by studying thermal conductivity, κ, and the heat capacity per unit volume ρCp of the depressurized glass. We use glycerol for the purpose and study first the changes in the features of κ and of ρCp during glass formation on cooling under a set of different p. We then partially depressurize the glass and study the effect of the p-induced instability on the features of κ and ρCp as the glass is isobarically heated to the liquid state. At a given low p, the glass configuration that was formed by cooling at high-p had a higher κ than the glass configuration that was formed by cooling at a low p. The difference is more when the glass is formed at a higher p and/or is depressurized to a lower p. On heating at a low p, its κ decreases before its glass-liquid transition range is reached. The effect is the opposite of the increase in κ observed on heating a glass at the same p under which it was formed. It is caused by thermally assisted loss of the added incompatibility of configurational and vibrational states of a high-p formed glass kept at low p. If a glass formed under a low-p is pressurized and then heated under high p, it would show the opposite effect, i.e., its κ would first increase to its high p value before its glass-to-liquid transition range.
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Affiliation(s)
- Ove Andersson
- Department of Physics, Umeå University, 901 87 Umeå, Sweden
| | - G P Johari
- Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario L8S 4L7, Canada
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13
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Tylinski M, Chua YZ, Beasley MS, Schick C, Ediger MD. Vapor-deposited alcohol glasses reveal a wide range of kinetic stability. J Chem Phys 2016; 145:174506. [DOI: 10.1063/1.4966582] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- M. Tylinski
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
| | - Y. Z. Chua
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - M. S. Beasley
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
| | - C. Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - M. D. Ediger
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
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