Testing of mode-coupling theory through impulsive stimulated thermal scattering

Halalay, Ion C.; Yang, Yu; Nelson, Keith A.

doi:10.1080/00411459508203944

Cited by 9 publications

(5 citation statements)

References 28 publications

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“…From figure 5 it appears that the crossover to the CD limit is always observed at a very similar correlation time, − lg(τ α /s) = 8-9; comparing the so-defined T x with T c as obtained by a conventional MCT analysis, we find a strong correlation. This is most easily demonstrated by plotting the temperature at which a correlation time of the order of lg(τ α /s) = −8 is found against the reported critical temperature T c [4,5,8,9,22,23]. This is tested in figure 7.…”

Section: Discussionmentioning

confidence: 99%

Evolution of the dynamic susceptibility of simple glass formers in the strongly supercooled regime

Adichtchev

Blochowicz

Gainaru

et al. 2003

J. Phys.: Condens. Matter

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We discuss dielectric and light scattering susceptibility spectra of simple glass formers at temperatures above as well as below the critical temperature of the mode coupling theory (MCT). Close to Tg the systems are characterized by the presence of a pronounced excess wing (type A glass formers). The data are analysed within a phenomenological approach, on the one hand, and within MCT, on the other. Among other work we present a complete interpolation of the dielectric data for glycerol (Lunkenheimer et al2000 Contemp. Phys. 41 15). The crossover temperature Tx, defined by the emergence of the excess wing upon cooling, is extracted from the phenomenological analysis and found to agree well with the critical temperature Tc, extracted from the MCT analysis at high temperatures. Below Tx the evolution of the susceptibility is characterized by a universal appearance of the excess wing. No difference is observed for the non-fragile system with respect to fragile glass formers provided that the wing parameters are studied as a function of the correlation time τα. Finally, a generalized scaling for the susceptibility minimum is proposed which is a phenomenological extension of that of MCT but now also includes the data below Tc.

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Section: Discussionmentioning

confidence: 99%

Evolution of the dynamic susceptibility of simple glass formers in the strongly supercooled regime

Adichtchev

Blochowicz

Gainaru

et al. 2003

J. Phys.: Condens. Matter

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“…In physical terms, all observable dynamics follows the dynamics of density fluctuations. This appears to be the case for relatively simple liquids like a concentrated aqueous LiCl solution and the molten salt [KNO 3 ] 0.6 [Ca(NO 3 ) 2 ] 0.4 [35,36]. However, Nagel and co-workers [37,38] have shown that in some low-molecular-weight liquids (salol, glycerol, propylene glycol), the dielectric loss (ω) does not exhibit a minimum at frequencies where there is a minimum in susceptibility spectra χ (ω) as determined from light and neutron scattering.…”

Section: Discussionmentioning

confidence: 99%

A mode-coupling theory catastrophe scenario description of relaxations in semicrystalline nylons

Halalay¹

1996

J. Phys.: Condens. Matter

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In the conception of mode-coupling theory the liquid-glass transition is due to topological singularities (mathematical catastrophes) in a system's parameter space. It is shown that previously published dielectric relaxation data for a number of semicrystalline polymers (polyalanine, polyglycine, nylon 3 and nylon 4) exhibit the characteristic signatures for an A 4singularity: inflection points, linear regions in ln(ω), 1/f noise regions, as well as a double minimum. Besides agreeing qualitatively with mode-coupling theory predictions, the data can also be described quantitatively with the A 4 -scenario.

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“…Further characterization of the relaxation mode at this wave vector is not possible, although ISTS measurements of acoustic frequencies and damping rates have been used to elucidate faster structural relaxation dynamics. 8,9,16 Charac-terization of the relaxation mode at higher temperatures was achieved with larger scattering wave vectors, at which the acoustic frequency was higher. Below 367.0 K, the structural relaxation dynamics become comparable to or slower than the thermal diffusion rate ⌫ H , which prevents further characterization of the relaxation mode at this wave vector.…”

Section: Methodsmentioning

confidence: 99%

“…4,5 PCS experiments 6,7 have revealed stretchedexponential ␣ relaxation dynamics in CKN on microsecond and slower at temperatures near the liquid-glass transition temperature T g . Impulsive stimulated scattering measurements on CKN, conducted with an early version of the experimental apparatus, 8,9 provided access to some of the intermediate temporal range with a signal-to-noise ratio insufficient for examination of the Debye-Waller factor. Recent ISTS measurements on the molecular glass former salol 10,11 demonstrated the current capabilities for reliable determination of f q (T), and showed the predicted temperature-dependent square-root cusp at a temperature which matched the value of T c determined through neutron scattering measurements of f q (T), 12 discussed below.…”

Section: Related Experimental Measurementsmentioning

confidence: 99%

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

Yang¹,

Nelson²

1996

The Journal of Chemical Physics

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Articles you may be interested inCombined isothermal and thermally stimulated depolarization measurements in polymers interpreted with the modified coupling model of relaxation Impulsive stimulated light scattering experiments were carried out on an ionic glass former Ca 0.4 K 0.6 ͑NO 3 ͒ 1.4 to determine the temperature dependence of the Debye-Waller factor f q (T) in the q→0 limit and to investigate the structural relaxation dynamics. A square-root cusp anomaly was observed in f q→0 (T) at a crossover temperature T c of 378 K. This and the relaxation dynamics observed were consistent with predictions of the mode-coupling theory of the liquid-glass transition.

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Testing of mode-coupling theory through impulsive stimulated thermal scattering

Cited by 9 publications

References 28 publications

Evolution of the dynamic susceptibility of simple glass formers in the strongly supercooled regime

Evolution of the dynamic susceptibility of simple glass formers in the strongly supercooled regime

A mode-coupling theory catastrophe scenario description of relaxations in semicrystalline nylons

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

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