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


Martedì 6 dicembre 2016, ore 17.30
Scuola Superiore di Catania
Aula Magna, Villa San Saverio

Relatore: Matthias Wuttig
RWTH Aachen University of Technology, Germany

ABSTRACT: 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 resonance 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’

WuttigSPEAKER'S BIO: Matthias Wuttig is a Full Professor of Experimental Physics at Aachen University (Germany). He has been visiting professor in many Universities and Research Centers (Almaden IBM Research Center San Josè, Lawrence Berkeley National Laboratory, AT&T Bell Laboratories, CNRS Marseille, Shangai, Singapore, Zhejiang) and Dean of the Faculty of Mathematics, Computer Science an Natural Sciences at Aaachen. ERC Advanced Grantee in 2013 he is author of over 500 papers (more than 20 of which in Nature or Science) with more than 20,000 citations and an h-index of 70.
Professor Wuttig is among the pioneers of phase change memories a new revolutionary type of non-volatile memory where information is saved by switching locally between an amorphous and crystalline phase.

Per informazioni: Dott.ssa Maria Sanfilippo - E-mail: - Tel: 0952338526