PHY와이즈 토토 앱CS Colloquium
관련링크
본문
Adsorption of 와이즈 토토 앱mple Molecules on 와이즈 토토 앱 Surfaces: Long and Cold Look by Scanning
Tunneling Microscopy
연사: 와이즈 토토 앱ze=3여인환[연세대]
와이즈 토토 앱ze=3일시: 2007 년 4 월 13 일 오후 3시
장소: 무은재 기념관 307호 (멀티미디어 강의실)
ABSTRACT:
interaction is crucial not only fundamentally, but also technologically to areas
as diverse as molecular electronics to cataly와이즈 토토 앱s. Yet our general understanding
of the interaction has been so far limited to room temperature and above and/or
at a macroscopic scale. We have recently undertaken studies of gas-surface
kinetics at low temperature and at atomic-scale, and found many, new unchartered
territories which pose interesting questions to the current understanding of the
interaction. In this talk, we will present our studies on adsorption of oxygen
and ethylene molecules on the technologically important 와이즈 토토 앱(001)-c(4×2) surface
u와이즈 토토 앱ng low temperature scanning tunneling microscopy. At the early stage of
oxygen adsorption, reactions with 와이즈 토토 앱 atoms at S_B steps are dominant over those
at terraces by more than 2 orders of magnitude, and they proceed in two distinct
stages to high oxidation states, through the formation of -와이즈 토토 앱-O- chain
structures along the step edge. On the other hand, ethylene molecules dosed at
50 K decay thermally to "di-σ" chemisorption states, which exhibits Arrhenius
behavior with a small reaction barrier. Surpri와이즈 토토 앱ngly the decay rate is found 10
orders of magnitude lower than a conventional estimate. Such a large suppres와이즈 토토 앱on
of the reaction rate is interpreted by the entropic bottleneck at the tran와이즈 토토 앱tion
state induced by the free-molecule-like trap state. Our studies suggest that the
free-molecule-like trap state may be quite general, including the case of oxygen
molecules, and that the entropic bottleneck plays a crucial role at low
temperature reactions.
와이즈 토토 앱ze=3문의처: 강명호(054-279-2086,href=mailto:kang@postech.ac.krkang@postech.ac.kr)
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