<注：本视频仅用于学术交流，版权归报告人所有>

►【国际合作研究中心学术报告】

报告题目: The Role of a Fragile-to-Strong Crossover in Crystallization of Glasses for Phase-Change Memory Applications

报告人：Dr. Jiri Orava

           IFW Dresden, Institute for Complex Materials, Germany

时间：2019年10月17日（周四）下午2点

地点：物理所M253会议室

Abstract:

In this talk, we will briefly introduce the characterization of crystallization mechanisms and dynamics in supercooled liquid: (i) by newly-emerging experimental techniques, allowing study of a wider temperature range of the existence of supercooled liquid, and measuring up to the maximum in the crystallization rate (mainly crystal-growth rate, U(T)) with high temporal resolution; and (ii) by computer simulations revealing the atomistic origin of crystallization and able to probe the early stages of nucleation processes which are difficult to access experimentally.

We will show that the existence of a fragile-to-strong crossover in supercooled-liquid state is of fundamental interest and furthermore is of considerable practical importance. A fragile-to-strong crossover in the liquid phase of the chalcogenide forming the active layer of a phase-change memory device may help to improve the long-term stability (data retention) at temperatures somewhat above ambient, while permitting fast writing (i.e. crystallization) at high temperatures. The crossover thus can help to meet the contradictory needs for fast switching and good data retention in phase-change memory devices. We will also hint on the structural origin of such a crossover and relate its temperature dependence to the crystallization mechanism.

Brief CV of Dr. Jiri Orava:

Dr. Jiri Orava obtained his Ph.D. degree from the University of Pardubice, the Czech Republic in 2009. Since then, he has been working as a postdoctoral researcher at the University of Cambridge (UK), Tohoku University (Japan) and Leibniz Institute for Solid State and Materials Research Dresden (Germany). His research interests mainly include physical-chemical properties of metallic glasses, tailoring the relationship between structure and macroscopic properties of glasses, synthesis, physical-chemical properties of chalcogenide glasses, chalcogenide phase-change materials for non-volatile computer memory, crystallization and stability of glass-forming liquids, glasses and glass-ceramics for optics and photonics.