报告题目: |
Spinning C60 molecules: how inter-molecular interaction leads to phase transitions within a monolayer of fullerenes |
报告人: |
Igor V. Shvets |
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Professor in School of Physics at Trinity College Dublin
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报告时间: |
2012-07-05 16:00 |
报告地点: |
理科楼B315室 |
主办单位: |
物理系 |
简介: |
There is currently much interest in using individual molecules as electronic switches. In this study we form a very regular layer of C60 molecules on the WO2/W(110) surface, the C60 layer being only one molecule thick. We can probe individual molecules with a very high resolution using STM with a single crystalline probe. The high resolution of our technique allowed detecting rotation of individual molecules within the regular layer. Temperature of the sample could be altered during the experiment. We found the molecules in the layer spin continuously if the temperature is above 259 K. Below 220 K the molecules become static as spinning freezes out. The two transitions at 259 K and 220 K are identified as structural and kinetic transitions respectively. Different types of molecular nanomotion, such as rotation, spinning, and switching between different orientations, have been observed. STM measurements are supported by density functional theory calculations, which provide confirmation of different orientations of C60 on the WO2 thin film. |
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