In-situ TEM Observation Of Electron Irradiation Induced Shape Transition Of Elongated Gold Nanoparticles Embedded In Silica

¹School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, New Delhi 110075, India

²Functional Nanomaterials, Institute for Materials Science, University of Kiel, Kaiserstrasse 2, 24143 Kiel, Germany

³Department of Material Science and Engineering, University of Sheffield, Sheffield, South Yorkshire, UK

⁴Inter University Accelerator Centre, Post Box -10502, New Delhi 110067, India

Adv. Mater. Lett., 2013, Ion Beam Special Issue, 4 (6), pp 444-448

DOI: 10.5185/amlett.2012.ib.111

Publication Date (Web): Mar 16, 2013

Copyright © IAAM-VBRI Press

E-mail: smiuac@gmail.com

Abstract

Elongated Au nanoparticles (NPs) embedded in silica matrix were fabricated by 100 MeV Ag ion irradiation of 3 MeV Au ion implanted SiO₂/Si(100) substrates, annealed at 1050^oC. Electron-beam-induced shape evolution of elongated Au NPs embedded in SiO₂ has been studied by high resolution transmission electron microscopy. Electron beam irradiation resulted in a decrease in the aspect ratio of Au NPs from ~ 1.4 to 1 with increase in irradiation time. The observed ellipsoidal-to-spherical shape transition of Au NPs has been ascribed mainly to the cumulative effects of electron beam induced heating, softening of silica matrix and radiation enhanced diffusion of knock-on displaced O and Si atoms, resulting in local stress relaxation.

Keywords

Gold nanoparticles, electron beam, transmission electron microscopy.