Please use this identifier to cite or link to this item:
Title: A New Route for the Fabrication of Nanoparticles in Superfluid Helium
Authors: Spence, Daniel James
Supervisors: Yang, Shengfu
Binns, Chris
Award date: 1-Dec-2014
Presented at: University of Leicester
Abstract: This project intends to establish a new route for the fabrication of nanoparticles using superfluid helium droplets as the growth medium, which offers a high degree of control over the growth of nanoparticles, allowing tailoring to specific applications. Starting from the characterization of the UHV superfluid helium droplet source, we progressively add more and more dopants to the droplets, leading to the formation of small clusters composed of a few molecules and/or metal atoms, and large nanoparticles composed of >104 atoms. The helium droplet source and small clusters are characterized using mass spectrometry while nanoparticles are investigated by transmission electron microscope imaging. By sequential doping we have obtained binary clusters, unlocking the possibility of producing heterogeneous clusters of any two or more materials. In addition, we have fabricated core-shell nanoparticles, and have provided microscopy images that clearly show core-shell structure for nanoparticles fabricated by this route for the first time. Finally, in this project we have obtained the first direct evidence for the presence of quantized vortices in nanoscale superfluid helium, which are then utilized as templates for the growth of nanowires. This opens up new a landscape of helium nanodroplet technology and new possibilities for nanoscience and nanotechnology.
Type: Thesis
Level: Doctoral
Qualification: PhD
Rights: Copyright © the author. All rights reserved.
Appears in Collections:Theses, Dept. of Chemistry
Leicester Theses

Files in This Item:
File Description SizeFormat 
2014spencedjphd.pdf9.48 MBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.