Dynamics of sorbitol and maltitol over a wide time-temperature range

Faivre, Annelise; Niquet, G; Maglione, Mario; Fornazero, J.; Jal, J. F.; David, Laurent

doi:10.1007/s100510050856

Cited by 83 publications

(63 citation statements)

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“…3.12) [35]. The latter is either somewhat larger [36,37] or comparable [37] to that of the β-process. Another is the so-called α′-relaxation process that is observed in metallic [38] as well as polymeric glasses [39].…”

Section: Glass Transitionmentioning

confidence: 80%

“…Although the activation energy has not been reported for this process, the slope of the respective Arrhenius plot is significantly larger than that for the β-relaxation. For the latter, the activation energies have been reported to be 62 [73], 57 [74], and 71 [35] kJ mol…”

Section: Isoconversional Treatmentmentioning

confidence: 97%

“…They have progressively smaller activation energies, each of which being smaller than the typical values found for the α-relaxation. Mt is known [73] to demonstrate the nonequilibrium α-mode. Although the activation energy has not been reported for this process, the slope of the respective Arrhenius plot is significantly larger than that for the β-relaxation.…”

Section: Isoconversional Treatmentmentioning

confidence: 99%

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Physical Processes

Vyazovkin

2015

Isoconversional Kinetics of Thermally Stimulated Processes

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Section: Glass Transitionmentioning

confidence: 80%

Section: Isoconversional Treatmentmentioning

confidence: 97%

Section: Isoconversional Treatmentmentioning

confidence: 99%

See 1 more Smart Citation

Physical Processes

Vyazovkin

2015

Isoconversional Kinetics of Thermally Stimulated Processes

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“…(iii) Johari-Goldstein type β-process (secondary process in the context of dielectric relaxation) [8,9,10,11,12,13] merges into the α-relaxation around T D , extrapolating the Arrhenius-type temperature dependence below T g of the β-relaxation times [6,14,15,16,17,18,19].…”

mentioning

confidence: 99%

Merging of α and slow β relaxation in supercooled liquids

2002

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Dielectric relaxation spectroscopy (1 Hz -20 GHz) has been performed on supercooled glassformers from the temperature of glass transition (Tg) up to that of melting. Precise measurements particularly in the frequencies of MHz-order have revealed that the temperature dependences of secondary β-relaxation times deviate from the Arrhenius relation in well above Tg. Consequently, our results indicate that the β-process merges into the primary α-mode around the melting temperature, and not at the dynamical transition point T ≈ 1.2Tg.PACS numbers: 64.70. Pf, 77.22.Gm, In recent years, much of the focus on glassy dynamics has been shifting to a considerably higher temperature than T g , the glass-transition one [1,2,3,4]. The topical temperature is located around T D ≡ 1.2T g , where the dynamics of supercooled liquids has been found to change fairly. So far, there have been observed the following phenomena:(i) Rössler scaling reveals that, when cooled, the Debye-Stokes-Einstein relation becomes invalid around T D [5,6]. This indicates a change of diffusion mechanism there.(ii) Stickel analysis [7] clarifies that temperature dependence of viscosity changes around T D . Therefore, in order to fit the primary α-relaxation time τ α using the Vogel-Fulcher-Tamman (VFT) relation,the coefficients (τ 0 , C, T 0 ) have to vary at T B ≈ T D . This suggests that the mechanism of slow structural-relaxation makes some alternation there.(iii) Johari-Goldstein type β-process (secondary process in the context of dielectric relaxation) [8,9,10,11,12,13] merges into the α-relaxation around T D , extrapolating the Arrhenius-type temperature dependence below T g of the β-relaxation times [6,14,15,16,17,18,19].Theoretically, the characteristic temperature T D is thought to be comparable to T C where the idealized Mode Coupling Theory (MCT) predicts a dynamical phase transition [20]. Indeed, the above first two phenomena (i, ii) can be regarded as indicators of the dynamical transition at T C . However, the MCT is irrelevant to the third one (iii), the bifurcation of α, β-modes; even the existence of the Johari-Goldstein type β-process cannot be derived.Furthermore, from experimental aspects, while the dynamical transition phenomena (i, ii) have been confirmed from either Rössler or Stickel plot definitely, the bifurcation of (iii) is inferred from the extrapolation. Actually, however, it remains an open problem as to whether the Arrhenius behavior of the β-process persists in higher temperatures near T D : the T D -decoupling of α, β-relaxations is not conclusive.This letter thus aims to investigate the secondary β-mode in high temperatures well above T g , by carrying out precisely the broad-band measurements of dielectric relaxation. Our main result is the following: as will be seen in Figures 2 and 5, the β-relaxation times deviate from the Arrhenius relation, indicating that the β-relaxation merges into the α-mode not at T D but around the Arrhenius-VFT crossover temperature T A (generally close to the melting one) where the temperatu...

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“…It has been reported that increasing frequency causes an increase in relaxation times and the energy of charge carrier [31]. The dispersion of relaxation times depends on the grain boundaries and various grains in all three structures [27][28][29][30][31]. The behavior of one peak in M may result from the existence of a particular density distribution profile of interface states at all three interfaces.…”

Section: Resultsmentioning

confidence: 99%

Investigation of dielectric properties of heterostructures based on ZnO structures

Selçuk

Orhan

Ocak

et al. 2017

Materials Science-Poland

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The voltage and frequency dependence of dielectric constant , dielectric loss , electrical modulus M , M , loss tangent tanδ and AC electrical conductivity σ AC of p-Si/ZnO/PMMA/Al, p-Si/ZnO/Al and p-Si/PMMA/Al structures have been investigated by means of experimental G-V and C-V measurements at 30 kHz, 100 kHz, 500 kHz and 1 MHz in this work. While the values of , , tanδ and σ AC decreased, the values of M and M increased for these structures when frequency was increased and those of p-Si/ZnO/Al and p-Si/PMMA/Al were comparable with those of p-Si/ZnO/PMMA/Al. The obtained results showed that the values of p-Si/ZnO/PMMA/Al structure were lower than the values of p

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Dynamics of sorbitol and maltitol over a wide time-temperature range

Cited by 83 publications

References 1 publication

Physical Processes

Physical Processes

Merging of α and slow β relaxation in supercooled liquids

Investigation of dielectric properties of heterostructures based on ZnO structures

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