物理學院“博約學術論壇”系列報告第18期        (2012年第7期)
 

題  目：Structure and dynamical properties in glass formation in CuZr metallic alloys
報告人：李茂枝 教授
單  位：中國人民大學物理系
時  間：2012年5月11日(星期五)上午10:00
地  點：中心教學樓701 

摘  要：
Describing the structure of amorphous materials such as metallic glasses and understanding the glass formation have been longstanding challenges in materials science. Despite enormous efforts and progress that have been made during the past several decades, a rational glass transition mechanism of real alloy systems is still absent. In this talk, I will talk about a distinct medium-range arrangement motif and an icosahedral two-phase structure observed in ZrCu binary metallic glasses. We find that the glass structure is a heterogeneous mixture of interpenetrating 13-atom icosahedral clusters connected in a string-like fashion forming a solid-like backbone network within a liquid-like matrix. A significant self-aggregation effect of icosahedral short-range order (ISRO) in high temperature ZrCu liquids is also discovered, which is highly consistent with that observed in atomic models of corresponding glass system. It is found that the development of ISRO upon cooling is driving the system into dynamical arrest. Moreover, the aggregation of ISRO remarkably enhances this effect and provides a positive feedback for the development of ISRO in the system. Due to its intrinsic non-space-filling character, the self-aggregation of ISRO results in a string-like network, expanding the slowing effects to a large portion of the system. When the network percolates, dynamics in the whole system is arrested, leading to a glass transition.

簡  歷：

2001年于中科院物理研究所獲得博士學位；
2001年至2007年在美國Ames國家實驗室做博士后和助理研究員；
2007年10月回國在中國人民大學任教。

先后從事包括表面生長動力學中表面納米結構的形成和穩定性、微觀原子擴散對表面形貌的形成機制、量子尺寸效應對表面納米結構形貌和穩定性的影響、非晶合金等體系中過冷液態和玻璃態的微觀結構、動力學性質和力學性質以及玻璃轉變機制等的理論和計算機模擬研究。

邀請人：姚裕貴  教授 

聯系方式：物理學院辦公室（68913163）
網    址： http://physics.bit.edu.cn/