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

S. Mohapatra1*, Y.K. Mishra2, J. Ghatak3, D.K. Avasthi4

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

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 1050oC. 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.

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