Linking rigidity transitions with enthalpic changes at the glass transition and fragility: insight from a simple oscillator model
Linking rigidity transitions with enthalpic changes at the glass transition and fragility: insight from a simple oscillator model
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将刚性转变与玻璃化转变和脆性的焓变化联系起来：来自简单振荡器模型的见解
DOI：
10.1088/0953-8984/22/28/285101
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
M. Micoulaut
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文献类型：
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作者：
M. Micoulaut
本文用低温MonteCarlo动力学方法研究了网络玻璃的刚性性质、玻璃化转变过程中的热可逆性和玻璃形成液体的强脆性行为之间的关系。该模型表明，一个菲利普斯最佳的玻璃形成与最小的结晶变化下得到的冷却/退火循环时，系统是最佳的谐波相互作用的约束，即当它是均衡刚性。对于这些特殊的系统具有几乎可逆的玻璃化转变，计算的弛豫时间的活化能也显示出最小值，这表明等静压刚性玻璃是强的（Arrhenius状）玻璃形成液体。硫属化物和氧化物玻璃形成液体的实验进行了讨论，在这个新的角度和确认硫属化物网络玻璃的理论预测，而弱相互作用（非共价，离子）系统的方法出现的局限性。
A low temperature Monte Carlo dynamics of a Keating-like oscillator model is used to study the relationship between the nature of network glasses from the viewpoint of rigidity, the thermal reversibility during the glass transition and the strong–fragile behaviour of glass-forming liquids. The model shows that a Phillips optimal glass formation with minimal enthalpic changes is obtained under a cooling/annealing cycle when the system is optimally constrained by the harmonic interactions, i.e. when it is isostatically rigid. For these peculiar systems with a nearly reversible glass transition, the computed activation energy for relaxation time shows also a minimum, which demonstrates that isostatically rigid glasses are strong (Arrhenius-like) glass-forming liquids. Experiments on chalcogenide and oxide glass-forming liquids are discussed under this new perspective and confirm the theoretical prediction for chalcogenide network glasses whereas limitations of the approach appear for weakly interacting (non-covalent, ionic) systems.