时间：2017年5月26日（星期五）下午14：30

地点：蒙民伟楼201室

报告人：香港科技大学韩一龙教授

报告题目：Melting and Premelting of Colloidal Crystals

Abstract:

We experimentally studied the melting behaviors of superheated colloidal crystals composed of diameter tunable microgel spheres by video microscopy with single-particle dynamics. The directly visualized nucleation precursors and homogeneous nucleation kinetics deviate from the classical nucleation theory as the degree of superheating increases up to the superheat limit. In the second part, we compared the surface premelting behaviors of monolayer and multilayer colloidal crystals composed of tunable attractive particles. The abnormal blocked premelting in monolayer crystals is triggered by a bulk solid-solid transition and terminated by a mechanical-instability-induced bulk melting. These experiments provide the first visualization of homogeneous melting and surface premelting at the single-particle level.

Refs:

Nature Reviews Materials, 1, 15011 (2016);

Nature, 531, 485 (2016);

Science, 338, 87 (2012).

报告人简历：
北京大学物理系本科（1998），芝加哥大学物理系博士（2003年），宾西法尼亚大学博士后。
从2007年起，任香港科技大学物理系助理教授，副教授。
2014年获全球华人物理与天文学会的亚洲成就奖 , 2016年获中国青年科技奖。