Conférence

Materials by Design: Taming Bond No. 6


Info

Dates
7 février 2019
Location
A142, Petits Amphithéâtres (bât. B7b)
Quartier Agora - allée du 6-Août 17
4000 Liège
See the map
Duration
1h00
Schedule
10h00

L'Unité de Recherche CESAM vous invite à la conférence du Professeur Matthias WUTTIG (RWTH Aachen University).

Materials by Design: Taming Bond No. 6

par le Pr. Matthias WUTTIG

It has been a long-time dream of mankind to design materials with tailored properties. In recent years, the focus of our work has been the design of phase change materials for applications in data storage. In this application, a remarkable property portfolio of phase change materials (PCMs) is employed, which includes the ability to rapidly switch between the amorphous and crystalline state. Surprisingly, in PCMs both states 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 employed. 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 well-defined group of materials utilizes a unique bonding mechanism (‘Bond No. 6’), which can explain many of the characteristic features of crystalline phase change materials. Different pieces of evidence for the existence of this novel bonding mechanism, which we have coined metavalent bonding, will be presented. This insight is subsequently employed to design phase change materials. Yet, the discoveries presented here also force us to revisit the concept of chemical bonds and bring back a history of vivid scientific disputes about ‘the nature of the chemical bond’.

Références

M. Zhu, O. Cojocaru-Mirédin, A.M. Mio, J. Keutgen, M. Küpers, Y. Yu, J.Y. Cho, R. Dronskowski, and M. Wuttig, Unique bond breaking in crystalline phase change materials and the quest for metavalent bonding, Advanced Materials 30, 1706735 (2018)

M. Wuttig, V.L. Deringer, X. Gonze, C. Bichara, J.-Y. Raty, Incipient Metals: Functional Materials with a Unique Bonding Mechanism, Advanced Materials 30, 1803777 (2018)

J.-Y. Raty, M. Schumacher, P. Golub, V.L. Deringer, C. Gatti, M. Wuttig, A Quantum-Mechanical Map for Bonding and Properties in Solids, Advanced Materials, 1806280  (2018)

Contact

Jean-Yves Raty

 

En savoir +

Des cristaux caractérisés par des liaisons « métavalentes » ont des propriétés spécifiques

UR CESAM

Solid State Physics, Interfaces and Nanostructures (SPIN)

Institute of Physics | Physics of New Material| RWTH Aachen University

 

 

 

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