Title: Template-assisted fabrication of nanowires

Authors: Prashant Kumar, M. Ghanashyam Krishna, A.K. Bhatnagar, A.K. Bhattacharya

Addresses: School of Physics, University of Hyderabad, Hyderabad 500046, India. ' School of Physics, University of Hyderabad, Hyderabad 500046, India. ' School of Physics, University of Hyderabad, Hyderabad 500046, India. ' Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK

Abstract: Template-assisted fabrication of nanowires in thin films of nickel and Gold is demonstrated. Ni thin films have been deposited on to Borosilicate Glass (BSG) and Si substrates by evaporation and Pulsed Laser Deposition (PLD) while gold was deposited by DC sputtering on to BSG substrates. The 10-200 nm thickness films were grown in to trenches scribed on to substrates. Nickel and Gold nanowires of diameter 50-400 nm have been found to form as a result of the template-assisted growth. The growth of the nanowires in both cases follows a pattern, as a function of thickness, that starts with self-organisation as nanoparticles then continuous nanowire and finally at higher thickness a combination of nanoparticles and continuous nanowires. Since formation of the nanowires is dependent on the self-shadowing phenomenon at the sidewalls of the trench, it was found that at large trench widths (50 µm) no nanowires could be formed. Length of the nanowires is completely dependent on the length of the trench whereas the diameter of the nanowires is dependent on the thickness of the thin film. Ferromagnetic Resonance (FMR) measurements on the Ni nanowires show magnetic anisotropy while the magnetotransport measurements reveal 3–4% of Magnetoresistance (MR). In the case of Gold nanowires additional plasmon resonance peaks have been observed, that were not present in the continuous thin films. This technique is shown to be a simple, yet effective way of fabricating nanowires with good control over dimensions of the nanowires as well as achieving novel properties.

Keywords: templates; nanowires; nanowire fabrication; magnetic anisotropy; nanotechnology; nanomanufacturing; thin films; nickel; gold; nanoparticles.

DOI: 10.1504/IJNM.2008.023144

International Journal of Nanomanufacturing, 2008 Vol.2 No.5, pp.477 - 495

Available online: 11 Feb 2009

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