Self-Organization in Network Glasses

最近，对网络眼镜进行的受控实验室实验已经能够破译无序系统自组织背后的物理原理。特别令人感兴趣的是发现了一个“中间相”，它受刚性和应力转变的限制。这一相表现出最不寻常的物理行为，包括玻璃化转变(Tg)，在TTg时，玻璃化转变的性质几乎完全是热逆转的，并且不随时间而老化。该奖项将集中于硫化物和氧化物玻璃，其中中间相的性质将使用拉曼散射和调制差示扫描量热实验来探索。这些玻璃被广泛应用于光子和电子应用中，在这些系统中发现这样的相将影响信息存储和存储应用。研究生、本科生和高中生将参加这个项目，接受这一领域的培训，并分享新玻璃相发现的兴奋。参与者和其他美国大学以及海外同事之间的思想和知识交流将继续加强这项研究。某些液体冷却后形成无序固体，由四面体或金字塔等特定构件组成的网络组成。这些固体被称为网络玻璃，二氧化硅就是一个熟悉的例子。在特定的条件下，网络玻璃可以自组织显示出有趣的物理性质，如热逆转的玻璃化转变，以及在低于玻璃化转变温度时结构中没有时间演化。导致无序网络自组织的原子结构排列具有科学意义，将使用复杂的光散射和热探测器进行研究。该项目将重点放在硫化物和氧化物玻璃上，预计会出现新的玻璃相。这些材料最广泛地应用于光子和电子应用中，在这些系统中发现这些相可能会对它们的应用产生深远的影响。包括一名女生在内的两名全日制研究生，两名兼职本科生和两名暑假打工的高中生将参与这项工作的科学发现阶段。

Controlled laboratory experiments on network glasses have recently permitted decoding the physical principles that underlie self-organization of disordered systems. Of particular interest, is the discovery of an "intermediate phase", which is bounded by the rigidity and stress transitions. This phase displays most unusual physical behavior including glass transitions (Tg) that are almost completely thermally reversing in character and not aging with time at T Tg. This award will focus on sulfide- and oxide-glasses, in which the nature of the intermediate phases will be explored using Raman scattering and modulated Differential Scanning Calorimetric experiments. These glasses are widely used in photonic and electronic applications, and the discovery of such phases in these systems will impact information storage and memory applications. Graduate, undergraduate, and high school students will participate in this project, receiving training in this field and also sharing in the excitement of discoveries of new glassy phases. An exchange of ideas and knowledge among the participants and colleagues at other US universities and abroad will be continue to strengthen the research. Certain liquids upon cooling form disordered solids that consist of networks of specific building blocks like tetrahedra or pyramids. These solids are called network glasses and silica is a familiar example. Under specific conditions network glasses can self-organize to display intriguing physical properties such as thermally reversing glass transitions and absence of time evolution in structure at temperatures below the glass transition temperature. The atomic structural arrangements that lead to self-organization of disordered networks are of scientific interest, and will be examined using sophisticated light scattering and thermal probes. This project will focus on sulfide- and oxide-glasses, in which novel glassy phases are expected. These materials are most widely used in photonic and electronic applications, and the discovery of such phases in these systems could have profound consequences on their applications. Two full time graduate students including a female student, two part-time undergraduate students, and two high-school students working in summer recess will be involved in the scientific discovery phase of this work.