Home Events Nanoclusters in the real world

Date

14 Sep 2022
Expired!

Time

4:00 pm - 5:00 pm

Nanoclusters in the real world

Title

Nanoclusters in the real world

Speaker

Prof. Richard E. Palmer (Nanomaterials Lab, Swansea University, UK)

Host

Prof. Kai Huang (GTIIT, Chemistry)

Time and Location

Sep. 14 2022, Wednesday, 4:00pm-5:00pm(China Time) E403 (Education Building, 4th floor)

Zoom

https://gtiit.zoom.us/j/94609938903 (ZOOM ID: 94609938903)

Abstract

Compared with the notional case of an isolated cluster (nanoparticle) at T=0, as addressed in some foundation theoretical treatments, two factors will shape the behaviour of clusters in the real, that is to say, experimental, world: (i) the radiative environment (including temperature and charged beams) and (ii) the material environment (including pressure, reactive gas and support). We will discuss five examples of the influence of these (coupled) factors; the work is mostly unpublished.

  1. Aberration-corrected electron microscopy at elevated temperature probes the melting and isomeric energy differences of arrays of size-selected gold clusters bound to point defects on a carbon surface (while subject to irradiation by 200keV electrons) [1,2].
  2. Video imaging of a single cluster at room temperature (plus beam heating) under conditions as (1) shows fluctuations between isomers, enabling both equilibrium properties and dynamical behaviour (branching ratios) to be explored.
  3. The case of 1 nm silver clusters (on carbon) stored in vacuum versus exposed to ambient shows dramatic differences in the isomer proportions (fcc dominant versus Ih dominant), probably due to the effect of sulphur contaminants on the structural energetics.
  4. For clusters assembled on the carbon surface from sputtered gold atoms, the transition from 2D to 3D morphology versus size appears to be delayed substantially compared with the free cluster.
  5. Implantation of lead clusters from the scaled-up MACS cluster beam into porous carbon supports provides a means to create an electrode architecture, illustrated by the electrochemical generation of oxidising species for water treatment.

References:

[1] D.M. Foster, R. Ferrando, R.E. Palmer, Nature Comms. 9 1323 (2018).

[2] D.M. Foster, T. Pavloudis, J. Kioseoglou, R.E. Palmer, Nature Comms. 10 2583 (2019).

Bio

https://www.researchgate.net/profile/Richard_Palmer6

Richard is Head of the Nanomaterials Lab, College of Engineering at Swansea University, UK, in his hometown. He is also Professor, School of Physics, Nanjing University, China. His research on atomic clusters includes fundamental studies of atomic structure and dynamics as well as scale-up. Other well-established research topics include atomic manipulation in STM and semiconductor nanofabrication. He was awarded an MA and PhD at Cambridge where he also held 1851, Clare College and Royal Society Fellowships. At Birmingham he founded the UK’s first centre for nanoscience. Honours include: IOP Boys Medal, Honorary Doctorate from Hasselt University, British Vacuum Council Yarwood Medal, EPSRC Senior Fellowship and Fellowships of IOP, RSC, Learned Society of Wales. He has published >450 papers, h = 63; also 20 families of patent applications. His work has led to a series of spin-out companies including Inanovate, Irresistible, Grove Nanomaterials, Nium. He is Editor-in-Chief of the journal Advances in Physics: X (Taylor and Francis) and Editor of the Elsevier Book Series ‘Frontiers of Nanoscience’.

 

Coordinator

Prof. Kai Huang

Speaker

Local Time

  • Timezone: America/New_York
  • Date: 14 Sep 2022
  • Time: 4:00 am - 5:00 am