The effect of thermal treatment on the magnetic properties of spinel ferrite nanoparticles in magnetic fluids

G. Kroņkalns - A. Dreimane - M. M. Maiorov

Institute of Physics, University of Latvia, 32 Miera str., Salaspils-1, LV-2169, Latvia

Abstract
Magnetic properties of ferrites are dependent on the crystalline structure and location of metal ions in the material. The most commonly used materials of nanoparticles in magnetic fluids are chemical stable spinel (2-3) ferrites. The preparation of ferrite nanoparticles for magnetic fluids synthesis needs a special technology. More commonly used is the wet chemical coprecipitation production technology of magnetic nanoparticles for MF. The ferrites synthesized by the wet chemical method have different magnetic characteristics if compared to the ferrites prepared by standard ceramic methods. In this paper, the physical properties of ultrafine complex spinel-type \Fe ₂\Co _0.3\Zn _0.6\Ca _0.1Ø ₄, \Fe _1.9\Cd _0.1\Mn _0.54\Zn _0.46Ø ₄, \Fe ₂\CoØ ₄ and \Fe ₂\Zn _0.6\Mn _0.3\Ca _0.1Ø ₄ ferrite particles and MF on its base, after their special thermal treatment, are studied. Tables 1, Figs 6, Refs 8.