题目：Phase Change Materials by Design: The Mystery of Resonance Bonding

报告人：M. Wuttig  RWTH Aachen University of Technology, Germany

地点： 教十二-201

时间： 6月9日，周五，13:40-14:50

摘要：

Phase change media utilize a remarkable property portfolio including the ability to rapidly switch between the amorphous and crystalline state, which differ significantly in their properties. This material combination makes them very attractive for data storage applications in rewriteable optical data storage, where the pronounced difference of optical properties between the amorphous and crystalline state is used. This unconventional class of materials is also the basis of a storage concept to replace flash memory.  This talk will discuss the unique material properties, which characterize phase change materials. In particular, it will be shown that only a rather small group of materials utilizes resonant bonding, a particular flavour of covalent bonding, which can explain many of the characteristic features of phase change materials. This insight is employed to predict systematic property trends and to explore the limits in stoichiometry for such memory applications. It will be demonstrated how this concept can be used to tailor the electrical and thermal conductivity of phase change materials. Yet, the discoveries presented here also force us to revisit the concept of resonance bonding and bring back a history of vivid scientific disputes about ‘the nature of the chemical bond’.

个人简介：

Prof. Dr. Mattias Wuttig is a Distinguished professor of Aachen University of Technology (RWTH), the speaker of the Strategy Board of RWTH AachenUniversity, the Ambassador Scientist of the Alexander von Humboldt foundation, a member of the Selection Committee of the Alexander von Humboldt Foundation, the speaker of the Collaborative Research Center (SFB 917): Nano-switches: Resistively switching chalcogenides for future electronic devices, and the director of JARA-Institute Green-IT. His other honors include the Gaede-Prize of the German Vacuum Society (1995), the Stanford R. Ovshinsky Prize (2007), the Einstein Professorship of the Chinese Academy of Sciences (2009), the Member of the Northrhine-Westphalian Academy of Sciences and Arts (2011). He is now leading the European Research Council (ERC) Advanced programme: Tuning Disorder in Chalcogenides to realize Advanced Functional Devices.

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