The Intermediate Phase in Network Glasses

网络眼镜的中间阶段

• 批准号: 0078361
• 负责人: Michael Thorpe
• 金额: $ 20.7万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2003-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0078361&HistoricalAwards=false
• 关键词: Intermediate; Phase; Network; Glasses

0078361ThorpeThis senior and distinguished PI works on properties of glasses but in the framework of a network model. In this view, which focuses on the geometric details such as network connectivity, the network is derived by putting the most important forces in the model to be infinite and the rest are set equal to zero. The resulting model is computationally manageable with a large number of particles. In this model, at a critical (as a function of) average coordination number (generally covalent glasses have large coordination number while the polymeric glasses in general have smaller coordination number), the states evolve in to a rigid and stressed state. However the numerical results show the existence if an intermediate state which is rigid but not stressed. This grant supports further work on this intermediate phase of a network glass. Recent experiments in chalcogenide glasses give preliminary evidence for an intermediate phase of this nature.%%%This senior and distinguished PI is a leader in the broad field of study involving glasses. In particular, guided by his belief that many properties of glasses can be studied using a geometric model, i.e. one made from sticks and balls, he has noticed the presence of curious phase of glass which may have been seen experimentally. Looking at glasses from their dependence on an average coordination number (number of atoms that a given atom may be connected to) there are two phases, one where the glass has a small coordination number, no rigidity and no accumulated stress while at large coordination number, the glass is rigid and it has accumulated stress. Near the transition, and a range of coordination number around the critical value, there is an intermediate phase corresponds to a rigid but unstressed glass. He plans to look at the observable properties of state.***

0078361Thorpe这位资深而杰出的PI研究玻璃的性质，但在网络模型的框架内。 在这个视图中，它侧重于几何细节，如网络连接，网络是通过将模型中最重要的力设置为无穷大，其余的设置为零来导出的。 由此产生的模型是计算管理与大量的粒子。 在该模型中，在临界平均配位数（作为平均配位数的函数）（通常共价玻璃具有大的配位数，而聚合物玻璃通常具有较小的配位数）下，状态演变为刚性和应力状态。 然而，数值结果表明，如果存在一个中间状态，这是刚性的，但没有应力。 该基金支持网络玻璃中间阶段的进一步工作。最近在硫系玻璃中的实验给出了这种中间相的初步证据。这位资深而杰出的PI是涉及眼镜的广泛研究领域的领导者。 特别是，他的信念，许多性质的玻璃可以研究使用几何模型，即一个由棍棒和球，他注意到存在的好奇阶段的玻璃可能已经看到实验。 从玻璃对平均配位数（给定原子可连接的原子数）的依赖性来看，存在两个阶段，一个阶段是玻璃具有小配位数，没有刚性且没有累积应力，而在大配位数下，玻璃是刚性的且具有累积应力。 在过渡区附近，配位数在临界值附近，存在一个中间相，对应于刚性但无应力的玻璃。 他计划研究状态的可观察属性。