题 目：Superfluid Helium: A New Frontier of NanoChemistry
Helium droplets are clusters of helium whose size can vary over a huge range, spanning a few dozen to in excess of 1011 helium atoms.[[S. Yang and A. M. Ellis, Chem. Soc. Rev. 42, 472-484 (2013).]]They possess some unique properties that are important for both physical chemistry and nanoscience, such as 1) a very low temperature (0.37 K), 2) superfluidity, 3) the ability to add materials sequentially, and 4) the chemical inertness of helium.This presentation will focus on the recent progress in nanochemistry using superfluid helium droplets as the nanoreactors in my group.A series of exploratory experiments will be reported, including the fabrication of single crystalline nanoparticles, core-shell nanoparticles and nanowires.[[A. Boatwright, C. Feng, D. Spence, E. Latimer, C. Binns, A. M. Ellis and S. Yang, Faraday Disc. 162, 113-124 (2013).],[E. Latimer, D. Spence, C. Feng, A. Boatwright, A. M. Ellis and S. Yang, Nano Lett.14, 2902 (2014).]] A major breakthrough in nanomagnetics, namely, ferromagnetism in antiferromagnetic chromium,[[ S. Yang, C. Feng, D. Spence, A. Al Hindawi, E. Latimer, A. M. Ellis, et al., Adv. Mater. 29, 1604277 (2017).]] and ferromagnetic nanoparticles with the atomic magnetic moments,[[S. Yang, C. Feng, D. Spence, E. Latimer, A. M. Ellis, C. Binns, D. Peddis, S. S. Dhesi, K. N. Trohidou, Nature (in preparation). ]] will be highlighted. Finally, striking observations of multiply quantized vortices in superfluid 4He and single Au atom catalyzed ion-molecule reactions will be addressed.
Prof. Shengfu Yangobtained a BSc degree in Tsinghua University, a MSc degree in Dalian Institute of Chemical Physics and a PhD degree at University of Science and Technology of China. He has worked in several world-class laboratories in China (USTC), France (Université Joseph Fourier), United States (Massachusetts Institute of Technology) and Finland (University of Helsinki), where he led a number of research programmes and acquired a wide range of experience in physical chemistry.He joined the University of Leicester in 2003 and was awarded a prestigious EPSRC Advanced Research Fellowship in 2006, before being appointed to an associate professorship in 2011. At Leicester, his research focuses on superfluid helium droplets, covering both Physical Chemistry and NanoChemistry. He is currently an international leader in novel nanoscience based on superfluid helium.