Self-Organization in Network Glasses

最近，在网络眼镜上进行的受控实验室实验已经允许解码无序系统自组织的物理原理。 特别感兴趣的是，发现了一个“中间相”，这是由刚性和应力转变的界限。该相显示出最不寻常的物理行为，包括玻璃化转变（Tg），其在性质上几乎完全是热可逆的，并且在Tg下不随时间老化。该奖项将集中在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进行探索。这些玻璃广泛用于光子和电子应用，在这些系统中发现这些相将影响信息存储和存储器应用。研究生、本科生和高中生将参与该项目，接受该领域的培训，并分享发现新玻璃相的兴奋。 参与者和美国其他大学及国外同事之间的思想和知识交流将继续加强研究。 某些液体在冷却时形成无序的固体，由特定的构建块组成的网络，如四面体或金字塔。这些固体被称为网络玻璃和二氧化硅是一个熟悉的例子。在特定条件下，网络玻璃可以自组织以显示有趣的物理性质，例如热逆转玻璃化转变和在低于玻璃化转变温度的温度下结构中不存在时间演变。导致无序网络自组织的原子结构安排具有科学意义，将使用复杂的光散射和热探针进行检查。该项目将集中在硫化物和氧化物玻璃，其中新的玻璃相的预期。这些材料最广泛地用于光子和电子应用，并且在这些系统中发现这些相可能对其应用产生深远的影响。两名全日制研究生（包括一名女学生）、两名兼职本科生和两名在暑假工作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.