The Synthesis of Silica-Coated Permalloy Nanoparticles Using a Water-in-Oil Microemulsion
A water-in-oil microemulsion method was used for the preparation of silica-coated permalloy (Ni0.80Fe0.20) nanoparticles. The particles were prepared by the reduction of their salts with sodium borohydride NaBH4 in a cationic water-in-oil (w/o) microemulsion of water/cetyltrimethyl- amonium bromide (CTAB) and n-butanol/isooctane at 25oC. According to the TEM and x-ray diffraction analyses, the synthesized material was in the form of nanoparticles. The magnetization of the silica-coated nanoparticles was lower than that of the uncoated particles, reflecting the influence of the nonmagnetic silica surface layer on the magnetization.
Dragan P. Uskokovic, Slobodan K. Milonjic, Djan I. Rakovic
I. Ban et al., "The Synthesis of Silica-Coated Permalloy Nanoparticles Using a Water-in-Oil Microemulsion ", Materials Science Forum, Vol. 494, pp. 161-166, 2005