Title: Synthesis and characterisation of dispersible Ni@NiO core shell magnetic nanoparticles by polyol method

Authors: O.D. Jayakumar, A.K. Tyagi

Addresses: Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. ' Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India

Abstract: Ni@NiO core shell nanoparticles, with crystalline Ni core, NiO shell and also partially and fully amorphous NiO shell, dispersible in alcohols, have been synthesised by a polyol method. The shell thickness has been varied by either changing the concentration of the NiO precursor solution used for making the shell, or by heating the as-synthesised core shell particles at 400°C. These particles were characterised using X-ray diffraction, high resolution TEM and magnetisation studies. HRTEM studies clearly indicated the crystalline fcc cubic Ni core and thin shells of amorphous and partially amorphous NiO particles, leading to a feeble exchange bias in M-H hysteresis loop. A significant reduction in ferromagnetic component has been observed on increasing the shell thickness, or on heating the parent core shell configuration. Dispersability and magnetic nature of these samples promises a wide spectrum of applications like data storage and magnetic recording, etc.

Keywords: polyol method; core shell particles; X-ray diffraction; magnetic properties; nanoparticles; naotechnology; shell thickness; synthesis; characterisation; nickel oxide; ferromagnetic core.

DOI: 10.1504/IJNT.2010.034693

International Journal of Nanotechnology, 2010 Vol.7 No.9/10/11/12, pp.852 - 860

Published online: 17 Aug 2010 *

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