Volume and enthalpy relaxation of a-Se in the glass transition region

Málek, Jiřı́; Svoboda, Roman; Pustková, Pavla; Čičmanec, Pavel

doi:10.1016/j.jnoncrysol.2008.11.014

Cited by 76 publications

(87 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…selenium [190]). For moderate departure from equilibrium, it has been, indeed, shown that volume and enthalpy relax in the same way when analyzed from the TNM approach or from the Adam-Gibbs model Figure 19.…”

Section: Adam and Gibbs Theorymentioning

confidence: 99%

Relaxation and physical aging in network glasses: a review

Micoulaut

2016

Rep. Prog. Phys.

View full text Add to dashboard Cite

Abstract. Recent progresses in the description of glassy relaxation and ageing are reviewed for the wide class of network-forming materials such as GeO 2 , Ge x Se 1−x , silicates (SiO 2 -Na 2 O) or borates (B 2 O 3 -Li 2 O), all of them having an important usefulness in domestic, geological or optoelectronic applications. A brief introduction of the glass transition phenomenology is given, together with the salient features that are revealed both from theory and experiments. Standard experimental methods used for the characterization of the slowing down of the dynamics are reviewed. We then discuss the important role played by aspect of network topology and rigidity for the understanding of the relaxation of the glass transition, while also permitting analytical predictions of glass properties from simple and insightful models based on the network structure. We also emphasize the great utility of computer simulations which probe the dynamics at the molecular level, and permit to calculate various structure-related functions in connection with glassy relaxation and the physics of ageing which reveals the off-equilibrium nature of glasses. We discuss the notion of spatial variations of structure which leads to the picture of "dynamic heterogeneities", and recent results of this important topic for network glasses are also reviewed.PACS numbers: 61.43. Fs, 64.70.kj Relaxation and physical ageing in network glasses 2 Figure 1. Typical network-forming glasses: a) A stoichiometric glass former (SiO 2 , B 2 S 3 ) whose structure and network connectivity can be altered by the addition (b) of 2-fold coordinated atoms (usually chalcogens, S, Se) that lead to cross-linked chains. The structure can also be depolymerized (c) by the addition of a network modifier (alkali oxides or chalcogenides, Na 2 O, Li 2 S, etc.). Glassy dynamics depends strongly on the network topology, i.e. the way bonds and angles arrange to lead to a connected atomic network. Note that only chalcogenides can produce a mixture of these three kinds of basic networks, e.g. (1-x)Ge y Se 1−y -xAg 2 Se [2], and for the latter system x=0 corresponds to case (b), y=33% corresponds to case (c), and both conditions together (x=0,y=33 %) to case (a).

show abstract

Section: Adam and Gibbs Theorymentioning

confidence: 99%

Relaxation and physical aging in network glasses: a review

Micoulaut

2016

Rep. Prog. Phys.

View full text Add to dashboard Cite

show abstract

“…q ? = 1000°C s -1 cycle and the a-Se enthalpy relaxation TNM parameters [24][25][26]. The lower pair of curves corresponds to the cooling and the consequent heating step expressed by means of fictive temperature T f .…”

Section: Correct Data Preparationmentioning

confidence: 99%

“…6a, the chosen experimental FSC data obtained for a-Se [13] (dashed lines) are compared to the theoretically simulated data (solid lines). The simulation was performed for the same temperature histories as those of the FSC measurements; TNM model parameters determined for a-Se from the conventional DSC measurements [24][25][26] were input into the simulation (Dh * /R = 42.75 kK, ln(A/ s) = -133, b = 0.65, x = 0.52). As is apparent, there is a clear disagreement between the two datasets.…”

Section: Tnm Description Versus Thermal Gradientsmentioning

confidence: 99%

Glass transition kinetics measured by fast scanning calorimetry

Svoboda

2015

J Therm Anal Calorim

Self Cite

View full text Add to dashboard Cite

Enthalpy relaxation data obtained for amorphous selenium by means of fast scanning calorimetry were described in terms of Tool-Narayanaswamy-Moynihan model. The effect of thermal gradients formed within the measured sample was found to explain the marked difference between the FSC and conventional DSC data obtained for a-Se. If the influence of thermal gradients is accounted for, the similar set of TNM parameters as obtained for a-Se from conventional DSC can be used to describe the FSC data. Temperature profiles of the thermal gradients as well as sources of additional uncertainties occurring within the introduced conception are discussed in detail. In addition, a normalization procedure accounting for the difference between the slopes of heat capacity in the glass and undercooled liquid regions was introduced. Correct data preparation was found to have a critical influence on the applied enthalpy relaxation evaluation procedures. Due to the unresolved issue of the prediction of manifesting thermal gradients found in case of the recent study on amorphous selenium, the FSC technique appears, for the time being, to have limited usage for enthalpy relaxation studies.

show abstract

“…The amorphous selenium has relatively low molecular weight polymer with low concentration of rings (Bichara & pellegatti, 1993, Caprion & Schober, 2000& 2002, Echeveria et. al., 2003, Malek et. al., 2009.…”

Section: Binary Chalcogenidesmentioning

confidence: 99%

Crystallization Kinetics of Chalcogenide Glasses

Singh¹

2012

Crystallization - Science and Technology

View full text Add to dashboard Cite

Volume and enthalpy relaxation of a-Se in the glass transition region

Cited by 76 publications

References 43 publications

Relaxation and physical aging in network glasses: a review

Relaxation and physical aging in network glasses: a review

Glass transition kinetics measured by fast scanning calorimetry

Crystallization Kinetics of Chalcogenide Glasses

Contact Info

Product

Resources

About