报告题目：Stressed patterns on Ag core/ SiO2 shell microstructures and their implication tophyllotaxis, wrinkle formation, nanowire growth and beyond



报告人： Prof. Cao Zexian, IOP, CAS



报告摘要：By coevaporating Ag2O and SiO, Ag core/ SiO2 shell microstructures can be formed on the path flying to the susbtrate. Depending on the eventual surface geometry of those microstructures falling onto the susbtrate, the patterns of most stressed sites (induced upon fast cooling) can be triangular tessellation, Fibonacci parastichous spirals or the X-pattern for strawberry. This helps establish the least elastic energy principle for phyllotaxis. Moreover, the birth of Ag particles out of the SiO2 placenta provides a modeling system for the investigation of catalytized growth of semiconductor nanowires. Other occurrences on the Ag core/ SiO2 shell microstructures provide the chances for the study of wrinkle formation on our face, bubble coalesce process, etc. Research results are published on Science (2005), APL (2004,2007, cover story) and PRL(2008).



报告人简历：

Prof. Cao Zexian,born in 1966, received his bachelor degree at department of physics, University of Science and Technology of China, in 1987, and he got his PhD degree in 1997 at University Kaiserslautern, Germany. He joined the institute of physics, CAS, in 1998. His main research interest includes thin film growth mechanism, materials science, nanostructures and devices, low-temperture plasma, microgravity,etc. Up to now he has published over 50 papers on international journals including Science and PRL, and over 40 papers in Chinese on physics education. He is now a freelance writer of physics in Chinese.



报告时间： 5月 19 日上午9：00

报告地点： B203

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