1. 연수기간 : 2021. 01. 27 ~ 2021. 02. 23 ( 총 27박 28일) ※ 코로나 2주 자가격리 제외
2. 연수국가 : 중국 톈진 (다등급)
3. 연수기관명 : Yanshan University
4. 연수자 : 석박사통합과정 4기 참여대학원생 1명
5. 연수주제 : Structure study on the two dimensional C60 polymer quenched from high pressure
6. 연수목적 및 필요성
- - One of the carbon allotropes, C60, is formed by 60-carbon atoms with a truncated icosahedron structure. Its uniqueness has attracted lots of researchers and been extensively studied since the first discovery in 1985 by Kroto et al. Plenty of derivatives (like C70, C80, alkali-doped C60) were discovered and formed a big family, fullerenes. Despite the numerous research work on the structure phase transitions of C60, many regions of P-T reaction diagram still remain unclear and therefore more advanced method to characterize the behavior under high pressure is required.
- - Under high pressure and high temperature treatment, the distance among C60 molecules gets shorted and they form into dimer or 1D-chained, 2D-layered polymers through [2+2] four-membered ring cycloaddition reactions. However, whether a further polymerized 3D-network structure is formed before the collapse of C60 cages is still an open question. Many models both in theoretical calculation and experiment were carried out but still no unambiguous conclusion is given. In order to get a deeper understanding of the behavior of C60 under compression, here we chose the 2D-tetragonal C60 polymer as the starting material and use diamond anvil cell to compress it up to 30 GPa and get the quenched samples for TEM experiment. This research is aiming to explore the possibilities of high-pressure induced 3D C60 polymer and identify the unclear part of P-T diagram regions.
7. 연수 기대효과
- Morphology changes in nanometer scale (TEM image) for two-dimensional C60 polymer under the influence of high pressure (up to 30 GPa).
- Structure transition of two-dimensional C60 polymer as a response to different applied pressure by using electron beam diffraction.
- Hybridized bonding (sp2-sp3 carbon) ratio change with pressure by studying electron energy loss spectroscopy (EELS).
8. 연수 수행방법
- Use diamond anvil cells to compress two-dimensional C60 polymer samples up to different pressures and release.
- Use the state-of-art FIB/TEM technology to prepare nanometer size samples and study for the morphology and structure changes under high pressure.