Impulsive stimulated thermal scattering study of α relaxation dynamics and the Debye–Waller factor anomaly in Ca0.4K0.6(NO3)1.4

Yang, Yu; Nelson, Keith A.

doi:10.1063/1.471782

Cited by 32 publications

(25 citation statements)

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“…This spectrum could be described by the T -independent master susceptibility χ denotes an α-peak position of the susceptibility spectrum. The found value T c is consistent with the one obtained by Yang and Nelson [37] for the Debye-Wallerfactor anomaly. It was shown in addition [52,53] that the identified β-correlator G(t) could account for the decay curves obtained for CKN by neutron spin echo measurements [54], a result supporting the factorization theorem (8).…”

Section: The First Scaling Lawsupporting

confidence: 91%

“…Formula (5) was shown to be compatible with the data for several systems. For example, the critical temperature T c ∼ 380 K was identified for the mixed salt 0.4Ca(NO 3 ) 2 0.6KNO 3 (CKN; T g = 333 K, T m = 438 K) [37]. It came as a surprise that the predicted square-root anomaly was found for standard systems like OTP or CKN within an easily excessible and often studied temperature range.…”

Section: Glass-transition Singularitiesmentioning

confidence: 99%

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The Essentials of the Mode-Coupling Theory for Glassy Dynamics

Gotze¹

1998

Condens. Matter Phys.

101

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The essential results of the mode-coupling theory for the evolution of structural relaxation in simple liquids such as the Debye-Waller-factor anomaly, the critical decay, von Schweidler's law, the α -and β -relaxation scaling, the appearance of two divergent time scales, and Kohlrausch's law for the α -process are explained, and their relevance to the understanding of experiments in glass-forming systems is described. : 64.70.Pf, 61.20.Lc In memoriam: I first met Dmitrii Nikolaevich Zubarev in 1969, when I came to Moscow to work with his team at the Steklov-Institute. Since then we met regularly. I always enjoyed discussing with him many open problems in statistical physics and I learned a lot from his unbiased and well contemplated views on various issues. I like to remember his gentleness, his warm hospitality, and the conversations with him on non-scientific matters. I dedicate this article to the memory of Dmitrii Nikolaevich with gratitude. Key words: mode-coupling theory, structural relaxation, glassy dynamics, bifurcation dynamics PACS

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Section: The First Scaling Lawsupporting

confidence: 91%

Section: Glass-transition Singularitiesmentioning

confidence: 99%

The Essentials of the Mode-Coupling Theory for Glassy Dynamics

Gotze¹

1998

Condens. Matter Phys.

101

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“…It predicts the divergence of structural relaxation times at an ideal glass transition temperature T c . Although the singularity is "avoided" in real glass formers, it is still signaled by asymptotic, so-called β-relaxation scaling laws for the dynamics at T ≈ T c [3], or a square-root singularity in the scattering intensities [4][5][6][7][8].On the low-temperature side, the replica method describes the properties of the (metastable) glassy states below T c [9, 10] yielding fewer but similar quantitative predictions [11,12]. Random-first-order transition (RFOT) theory [13,14] builds on top of replica results by advocating entropic nucleation processes to restore ergodicity below T c and predicts a debated divergence of a correlation length below the calorimetric glass transition.…”

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confidence: 99%

Qualitative features at the glass crossover

Rizzo¹,

Voigtmann²

2015

EPL

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We discuss some generic features of the dynamics of glass-forming liquids close to the glass transition singularity of the idealized mode-coupling theory (MCT). The analysis is based on a recent model by one of the authors for the intermediate-time dynamics (β relaxation), derived by applying dynamical field-theory techniques to the idealized MCT. Combined with the assumption of timetemperature superposition for the slow structural (α) relaxation, the model naturally explains three prominent features of the dynamical crossover: the change from a power-law to exponential increase in the structural relaxation time, the replacement of the Stokes-Einstein relation between diffusion and viscosity by a fractional law, and two distinct growth regimes of the thermal susceptibility that has been associated to dynamical heterogeneities.PACS numbers: 64.70.QTo describe how classical liquids arrest kinetically at the glass transition, is still a controversial issue within statistical physics. Starting from the high-temperature liquid state, it is natural to focus on the dramatic slowing down in the dynamics. Here the mode-coupling theory of the glass transition (MCT) is successful [1,2]. It predicts the divergence of structural relaxation times at an ideal glass transition temperature T c . Although the singularity is "avoided" in real glass formers, it is still signaled by asymptotic, so-called β-relaxation scaling laws for the dynamics at T ≈ T c [3], or a square-root singularity in the scattering intensities [4][5][6][7][8].On the low-temperature side, the replica method describes the properties of the (metastable) glassy states below T c [9, 10] yielding fewer but similar quantitative predictions [11,12]. Random-first-order transition (RFOT) theory [13,14] builds on top of replica results by advocating entropic nucleation processes to restore ergodicity below T c and predicts a debated divergence of a correlation length below the calorimetric glass transition.Several attempts have been made at "extended MCT" to incorporate such physics below T c : introducing further relaxation channels to the MCT equations [15][16][17][18][19][20][21], taking into account higher-order factorization of manyparticle density modes [22,23], considering generalizedhydrodynamic arguments [24], leading to time-dependent coupling coefficients [25], using ideas of RFOT theory [26], or within "naïve" MCT [27][28][29]. By and large, all remained rather empirical.One of us [30] has developed a new approach to ideal MCT based on the fact that close to T c , fluctuations will become important. The study of these fluctuations in a full-fledged dynamical context provides a crucial improvement on earlier static treatments [31]. After a complex field theoretical computation the original problem is mapped onto a rather intuitive model that extends the β-scaling laws (rather than full MCT, due to saddle-point approximations in its derivation) to a spatially inhomogeneous case where the distance to T c becomes a spatially fluctuating variable. The correspo...

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“…This two-step relaxation is thoroughly investigated, and it is established that MCT is able to explain, e.g. the following properties: (i) square-root cusp anomaly of the temperature dependence of the plateau height of the density time-correlator (called the non-ergodic parameter, NEP) [6], (ii) powerlaw time-dependence with von Schweidler exponents of the density time-correlator around the β-relaxation [7][8][9], (iii) time-temperature superposition principle realized by the Kohlrausch-Williams-Watts-type behavior of the density time-correlator at the α-relaxation [10]. On the * suzuki.koshiro@canon.co.jp other hand, MCT is marred with the problem that the NEP can survive for temperatures below the critical temperature T c , while it decays to zero in actual glassy states [4,11].…”

Section: Introductionmentioning

confidence: 99%

Nonequilibrium mode-coupling theory for uniformly sheared underdamped systems

Suzuki

Hayakawa

2013

Phys. Rev. E

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Nonequilibrium mode-coupling theory (MCT) for uniformly sheared underdamped systems is developed, starting from the microscopic thermostatted SLLOD equation, and the corresponding Liouville equation. Special attention is paid to the translational invariance in the sheared frame, which requires an appropriate definition of the transient time-correlators. The derived MCT equation satisfies the alignment of the wavevectors, and is manifestly translationally invariant. Isothermal condition is implemented by the introduction of the current fluctuation in the dissipative coupling to the thermostat. This current fluctation grows in the α-relaxation regime, which generates a deviation of the yield stress in the glassy phase from the overdamped case. Response to a perturbation of the shear rate demonstrates an inertia effect which is not observed in the overdamped case. Our theory turns out to be a non-trivial extension of the theory by Fuchs and Cates (J. Rheol. 53(4), 2009) to underdamped systems. Since our starting point is identical to that by Chong and Kim (Phys. Rev. E 79, 2009), the contradictions between Fuchs-Cates and Chong-Kim are resolved.

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Impulsive stimulated thermal scattering study of α relaxation dynamics and the Debye–Waller factor anomaly in Ca0.4K0.6(NO3)1.4

Cited by 32 publications

References 23 publications

The Essentials of the Mode-Coupling Theory for Glassy Dynamics

The Essentials of the Mode-Coupling Theory for Glassy Dynamics

Qualitative features at the glass crossover

Nonequilibrium mode-coupling theory for uniformly sheared underdamped systems

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