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Jiang C, Baggioli M, Douglas JF. Stringlet excitation model of the boson peak. J Chem Phys 2024; 160:214505. [PMID: 38832741 DOI: 10.1063/5.0210057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 05/20/2024] [Indexed: 06/05/2024] Open
Abstract
The boson peak (BP), a low-energy excess in the vibrational density of states over the Debye contribution, is often identified as a characteristic of amorphous solid materials. Despite decades of efforts, its microscopic origin still remains a mystery. Recently, it has been proposed, and corroborated with simulations, that the BP might stem from intrinsic localized modes involving one-dimensional (1D) string-like excitations ("stringlets"). We build on a theory originally proposed by Lund that describes the localized modes as 1D vibrating strings, but we specify the stringlet size distribution to be exponential, as observed in simulations. We provide an analytical prediction for the BP frequency ωBP in the temperature regime well below the observed glass transition temperature Tg. The prediction involves no free parameters and accords quantitatively with prior simulation observations in 2D and 3D model glasses based on inverse power law potentials. The comparison of the string model to observations is more uncertain when compared to simulations of an Al-Sm metallic glass material at temperatures well above Tg. Nonetheless, our stringlet model of the BP naturally reproduces the softening of the BP frequency upon heating and offers an analytical explanation for the experimentally observed scaling with the shear modulus in the glass state and changes in this scaling in simulations of glass-forming liquids. Finally, the theoretical analysis highlights the existence of a strong damping for the stringlet modes above Tg, which leads to a large low-frequency contribution to the 3D vibrational density of states, observed in both experiments and simulations.
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Affiliation(s)
- Cunyuan Jiang
- School of Physics and Astronomy, Shanghai Jiao Tong University, 200240 Shanghai, China
- Wilczek Quantum Center, Shanghai Jiao Tong University, 200240 Shanghai, China
- Shanghai Research Center for Quantum Sciences, 200240 Shanghai, China
| | - Matteo Baggioli
- School of Physics and Astronomy, Shanghai Jiao Tong University, 200240 Shanghai, China
- Wilczek Quantum Center, Shanghai Jiao Tong University, 200240 Shanghai, China
- Shanghai Research Center for Quantum Sciences, 200240 Shanghai, China
| | - Jack F Douglas
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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2
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Krivchikov A, Jeżowski A, Szewczyk D, Korolyuk OA, Romantsova OO, Buravtseva LM, Cazorla C, Tamarit JL. Role of Optical Phonons and Anharmonicity in the Appearance of the Heat Capacity Boson Peak-like Anomaly in Fully Ordered Molecular Crystals. J Phys Chem Lett 2022; 13:5061-5067. [PMID: 35652901 PMCID: PMC9189925 DOI: 10.1021/acs.jpclett.2c01224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
We demonstrate that the heat capacity Boson peak (BP)-like anomaly appearing in fully ordered anharmonic molecular crystals emerges as a result of the strong interactions between propagating (acoustic) and low-energy quasi-localized (optical) phonons. In particular, we experimentally determine the low-temperature (<30 K) specific heat of the molecular crystal benzophenone and those of several of its fully ordered bromine derivatives. Subsequently, by means of theoretical first-principles methods based on density functional theory, we estimate the corresponding phonon dispersions and vibrational density of states. Our results reveal two possible mechanisms for the emergence of the BP-like anomaly: (i) acoustic-optic phonon avoided crossing, which gives rise to a pseudo-van Hove singularity in the acoustic phonon branches, and (ii) piling up of low-frequency optical phonons, which are quasi degenerate with longitudinal acoustic modes and lead to a surge in the vibrational density of states at low energies.
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Affiliation(s)
- Alexander
I. Krivchikov
- Verkin
Institute for Low Temperature Physics and Engineering of the National
Academy of Sciences of Ukraine, 47 Nauky Avenue, Kharkiv 61103, Ukraine
| | - Andrezj Jeżowski
- Institute
of Low Temperature and Structure Research, Polish Academy of Sciences, 2 Okólna Strasse, 50-422 Wrocław, Poland
| | - Daria Szewczyk
- Institute
of Low Temperature and Structure Research, Polish Academy of Sciences, 2 Okólna Strasse, 50-422 Wrocław, Poland
| | - Oxsana A. Korolyuk
- Verkin
Institute for Low Temperature Physics and Engineering of the National
Academy of Sciences of Ukraine, 47 Nauky Avenue, Kharkiv 61103, Ukraine
| | - Olesya O. Romantsova
- Verkin
Institute for Low Temperature Physics and Engineering of the National
Academy of Sciences of Ukraine, 47 Nauky Avenue, Kharkiv 61103, Ukraine
| | - Lubov M. Buravtseva
- Verkin
Institute for Low Temperature Physics and Engineering of the National
Academy of Sciences of Ukraine, 47 Nauky Avenue, Kharkiv 61103, Ukraine
| | - Claudio Cazorla
- Grup
de Caracterizació de Materials, Departament de Fisica, EEBE,
and Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 10-14, 08019 Barcelona, Catalonia, Spain
| | - Josep Ll. Tamarit
- Grup
de Caracterizació de Materials, Departament de Fisica, EEBE,
and Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 10-14, 08019 Barcelona, Catalonia, Spain
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3
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Ren S, Zong HX, Tao XF, Sun YH, Sun BA, Xue DZ, Ding XD, Wang WH. Boson-peak-like anomaly caused by transverse phonon softening in strain glass. Nat Commun 2021; 12:5755. [PMID: 34599172 PMCID: PMC8486772 DOI: 10.1038/s41467-021-26029-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 09/14/2021] [Indexed: 11/09/2022] Open
Abstract
Strain glass is a glassy state with frozen ferroelastic/martensitic nanodomains in shape memory alloys, yet its nature remains unclear. Here, we report a glassy feature in strain glass that was thought to be only present in structural glasses. An abnormal hump is observed in strain glass around 10 K upon normalizing the specific heat by cubed temperature, similar to the boson peak in metallic glass. The simulation studies show that this boson-peak-like anomaly is caused by the phonon softening of the non-transforming matrix surrounding martensitic domains, which occurs in a transverse acoustic branch not associated with the martensitic transformation displacements. Therefore, this anomaly neither is a relic of van Hove singularity nor can be explained by other theories relying on structural disorder, while it verifies a recent theoretical model without any assumptions of disorder. This work might provide fresh insights in understanding the nature of glassy states and associated vibrational properties.
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Affiliation(s)
- Shuai Ren
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Hong-Xiang Zong
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Xue-Fei Tao
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Yong-Hao Sun
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Bao-An Sun
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - De-Zhen Xue
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Xiang-Dong Ding
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, 710049, Xi'an, China.
| | - Wei-Hua Wang
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.
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4
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Qiu Q, Bao JD. Debye Brownian oscillator and Debye-type noise: A series solution versus Monte Carlo simulation. Phys Rev E 2021; 104:014114. [PMID: 34412352 DOI: 10.1103/physreve.104.014114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 06/21/2021] [Indexed: 11/07/2022]
Abstract
For the Debye Brownian oscillator, we present a series solution to the generalized Langevin equation describing the motion of a particle. The external potential is considered to be a harmonic potential and the spectral density of driven noise is a hard cutoff at high finite frequencies. The results are in agreement with both numerical calculations and Monte Carlo simulations. We demonstrate abnormal weak ergodic breaking; specifically, the long-time average of the observable vanishes but the corresponding ensemble average continues to oscillate with time. This Debye Brownian oscillator does not arrive at an equilibrium state and undergoes underdamped-like motion for any model parameter. Nevertheless, ergodic behavior and equilibrium can be recovered concurrently using a strong bound potential. We give an understanding of the behavior as being the consequence of discrete breather modes in the lattices similar to the formation of an additional periodic signal. Furthermore, we compare the results calculated by cutting off separately the spectral density and the correlation function of colored noise.
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Affiliation(s)
- Qian Qiu
- Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Jing-Dong Bao
- Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
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5
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Collins CM, Daniels LM, Gibson Q, Gaultois MW, Moran M, Feetham R, Pitcher MJ, Dyer MS, Delacotte C, Zanella M, Murray CA, Glodan G, Pérez O, Pelloquin D, Manning TD, Alaria J, Darling GR, Claridge JB, Rosseinsky MJ. Discovery of a Low Thermal Conductivity Oxide Guided by Probe Structure Prediction and Machine Learning. Angew Chem Int Ed Engl 2021; 60:16457-16465. [PMID: 33951284 PMCID: PMC8362121 DOI: 10.1002/anie.202102073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Indexed: 12/04/2022]
Abstract
We report the aperiodic titanate Ba10 Y6 Ti4 O27 with a room-temperature thermal conductivity that equals the lowest reported for an oxide. The structure is characterised by discontinuous occupancy modulation of each of the sites and can be considered as a quasicrystal. The resulting localisation of lattice vibrations suppresses phonon transport of heat. This new lead material for low-thermal-conductivity oxides is metastable and located within a quaternary phase field that has been previously explored. Its isolation thus requires a precisely defined synthetic protocol. The necessary narrowing of the search space for experimental investigation was achieved by evaluation of titanate crystal chemistry, prediction of unexplored structural motifs that would favour synthetically accessible new compositions, and assessment of their properties with machine-learning models.
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Affiliation(s)
| | - Luke M. Daniels
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
| | - Quinn Gibson
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
| | - Michael W. Gaultois
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
- Leverhulme Research Centre for Functional Materials DesignThe Materials Innovation FactoryUniversity of Liverpool51 Oxford StreetLiverpoolL7 3NYUK
| | - Michael Moran
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
- Leverhulme Research Centre for Functional Materials DesignThe Materials Innovation FactoryUniversity of Liverpool51 Oxford StreetLiverpoolL7 3NYUK
| | - Richard Feetham
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
| | - Michael J. Pitcher
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
| | - Matthew S. Dyer
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
| | - Charlene Delacotte
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
| | - Marco Zanella
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
| | - Claire A. Murray
- Diamond Light SourceHarwell Science and Innovation CampusOxfordshireOX11 0DEUK
| | - Gyorgyi Glodan
- University of ManchesterDalton Cumbrian FacilityWestlakes Science ParkMoor RowCA24 3HAUK
| | - Olivier Pérez
- Laboratoire CRISMATENSICAEN6 boulevard du Maréchal Juin14050Caen Cedex 4France
| | - Denis Pelloquin
- Laboratoire CRISMATENSICAEN6 boulevard du Maréchal Juin14050Caen Cedex 4France
| | - Troy D. Manning
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
| | - Jonathan Alaria
- Department of PhysicsUniversity of LiverpoolOxford StreetLiverpoolL69 7ZEUK
| | - George R. Darling
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
| | - John B. Claridge
- Department of ChemistryUniversity of LiverpoolCrown StreetLiverpoolL69 7ZDUK
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6
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Collins CM, Daniels LM, Gibson Q, Gaultois MW, Moran M, Feetham R, Pitcher MJ, Dyer MS, Delacotte C, Zanella M, Murray CA, Glodan G, Pérez O, Pelloquin D, Manning TD, Alaria J, Darling GR, Claridge JB, Rosseinsky MJ. Discovery of a Low Thermal Conductivity Oxide Guided by Probe Structure Prediction and Machine Learning. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | - Luke M. Daniels
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - Quinn Gibson
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - Michael W. Gaultois
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
- Leverhulme Research Centre for Functional Materials Design The Materials Innovation Factory University of Liverpool 51 Oxford Street Liverpool L7 3NY UK
| | - Michael Moran
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
- Leverhulme Research Centre for Functional Materials Design The Materials Innovation Factory University of Liverpool 51 Oxford Street Liverpool L7 3NY UK
| | - Richard Feetham
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - Michael J. Pitcher
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - Matthew S. Dyer
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - Charlene Delacotte
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - Marco Zanella
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - Claire A. Murray
- Diamond Light Source Harwell Science and Innovation Campus Oxfordshire OX11 0DE UK
| | - Gyorgyi Glodan
- University of Manchester Dalton Cumbrian Facility Westlakes Science Park Moor Row CA24 3HA UK
| | - Olivier Pérez
- Laboratoire CRISMAT ENSICAEN 6 boulevard du Maréchal Juin 14050 Caen Cedex 4 France
| | - Denis Pelloquin
- Laboratoire CRISMAT ENSICAEN 6 boulevard du Maréchal Juin 14050 Caen Cedex 4 France
| | - Troy D. Manning
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - Jonathan Alaria
- Department of Physics University of Liverpool Oxford Street Liverpool L69 7ZE UK
| | - George R. Darling
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - John B. Claridge
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
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7
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Heat capacity signature of frustrated trimerons in magnetite. Sci Rep 2020; 10:10909. [PMID: 32616822 PMCID: PMC7331697 DOI: 10.1038/s41598-020-67955-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 05/28/2020] [Indexed: 11/08/2022] Open
Abstract
Recently it has been proposed that the long-range electronic order formed by trimerons in magnetite should be frustrated due to the great degeneracy of arrangements linking trimerons. This result has important consequences as charge ordering from the condensed minority band electrons leads to a complex 3D antiferro orbital order pattern. Further more, the corner sharing tetrahedra structure of spinel B-sites supports frustration for antiferromagnetic alignments. Therefore frustration due to competing interactions will itself induce disorder and very likely frustration in the spin orientations. Here we present very low temperature specific heat data that show two deviations to the magnons and phonons contributions, that we analyze in terms of Schottky-type anomalies. The first one is associated with the thermal activation across both ferroelastic twin and ferromagnetic anti-phase domains. The second Schottky-type anomaly displays an inverse (1/H) field dependence which is a direct indication of the disordered glassy network with macroscopically degenerated singular ground states.
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8
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Baggioli M, Zaccone A. Universal Origin of Boson Peak Vibrational Anomalies in Ordered Crystals and in Amorphous Materials. PHYSICAL REVIEW LETTERS 2019; 122:145501. [PMID: 31050477 DOI: 10.1103/physrevlett.122.145501] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/11/2019] [Indexed: 06/09/2023]
Abstract
The vibrational spectra of solids, both ordered and amorphous, in the low-energy regime, control the thermal and transport properties of materials, from heat capacity to heat conduction, electron-phonon couplings, conventional superconductivity, etc. The old Debye model of vibrational spectra at low energy gives the vibrational density of states (VDOS) as proportional to the frequency squared, but in many materials the spectrum departs from this law which results in a peak upon normalizing the VDOS by frequency squared, which is known as the "boson peak." A description of the VDOS of solids (both crystals and glasses) is presented starting from first principles. Without using any assumptions whatsoever of disorder in the material, it is shown that the boson peak in the VDOS of both ordered crystals and glasses arises naturally from the competition between elastic mode propagation and diffusive damping. The theory explains the recent experimental observations of boson peak in perfectly ordered crystals, which cannot be explained based on previous theoretical frameworks. The theory also explains, for the first time, how the vibrational spectrum changes with the atomic density of the solid, and explains recent experimental observations of this effect.
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Affiliation(s)
- Matteo Baggioli
- Instituto de Fisica Teorica UAM/CSIC, c/Nicolas Cabrera 13-15, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid, Spain
- Crete Center for Theoretical Physics, Institute for Theoretical and Computational Physics, Department of Physics, University of Crete, 71003 Heraklion, Greece
| | - Alessio Zaccone
- Department of Physics "A. Pontremoli", University of Milan, via Celoria 16, 20133 Milan, Italy
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, CB30HE Cambridge, United Kingdom
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB30AS Cambridge, United Kingdom
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9
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Romanini M, Tamarit JL, Pardo LC, Bermejo FJ, Fernandez-Perea R, Pratt FL. Implanted muon spin spectroscopy on 2-O-adamantane: a model system that mimics the liquid[Formula: see text]glasslike transitions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:085405. [PMID: 28095369 DOI: 10.1088/1361-648x/aa530d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The transition taking place between two metastable phases in 2-O-adamantane, namely the [Formula: see text] cubic, rotator phase and the lower temperature P21/c, Z = 4 substitutionally disordered crystal is studied by means of muon spin rotation and relaxation techniques. Measurements carried out under zero, weak transverse and longitudinal fields reveal a temperature dependence of the relaxation parameters strikingly similar to those exhibited by structural glass[Formula: see text]liquid transitions (Bermejo et al 2004 Phys. Rev. B 70 214202; Cabrillo et al 2003 Phys. Rev. B 67 184201). The observed behaviour manifests itself as a square root singularity in the relaxation rates pointing towards some critical temperature which for amorphous systems is located some tens of degrees above that shown as the characteristic transition temperature if studied by thermodynamic means. The implications of such findings in the context of current theoretical approaches concerning the canonical liquid-glass transition are discussed.
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Affiliation(s)
- M Romanini
- Grup de Caracterizacio de Materials, Departament de Fisica, ETSEIB, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalonia, Spain
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10
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Szewczyk D, Jeżowski A, Vdovichenko GA, Krivchikov AI, Bermejo FJ, Tamarit JL, Pardo LC, Taylor JW. Glassy Dynamics versus Thermodynamics: The Case of 2-Adamantanone. J Phys Chem B 2015; 119:8468-74. [PMID: 26073682 DOI: 10.1021/acs.jpcb.5b04240] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- D. Szewczyk
- Institute for Low Temperature and Structure
Research, Polish Academy of Scienceul. Okólna 2, 50-422 Wrocław, Poland
| | - A. Jeżowski
- Institute for Low Temperature and Structure
Research, Polish Academy of Scienceul. Okólna 2, 50-422 Wrocław, Poland
| | - G. A Vdovichenko
- B. Verkin Institute for Low Temperature Physics and Engineering of NAS Ukraine, 47 Lenin Avenue, Kharkov 61103, Ukraine
| | - A. I. Krivchikov
- B. Verkin Institute for Low Temperature Physics and Engineering of NAS Ukraine, 47 Lenin Avenue, Kharkov 61103, Ukraine
| | - F. J. Bermejo
- Instituto de Estructura
de la Materia, Consejo Superior de Investigaciones Cientficas, CSIC, Serrano
123, 28006 Madrid, Spain
| | - J. Ll. Tamarit
- Grup de Caracterització de Materials,
Departament de Física i Enginyieria Nuclear, ETSEIB, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalonia Spain
| | - L. C. Pardo
- Grup de Caracterització de Materials,
Departament de Física i Enginyieria Nuclear, ETSEIB, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalonia Spain
| | - J. W. Taylor
- Rutherford Appleton Lab, ISIS Facility, Didcot
OX11 0QX, Oxon, England
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