NiFe2O4 ultrafine particles prepared by co-precipitation/mechanical alloying

Nickel ferrite ultrafine particles have been prepared by the combination of co-precipitation and mechanical alloying. Sodium chloride was added in order to avoid agglomeration. This work has shown that nickel ferrite phase can be formed directly during mechanical milling of hydroxide precursor. Ultrafine NiFe2O4 particles were obtained after a simple washing process. The XRD study showed that sodium chloride can be efficiently removed during the washing with deionized water. These ultrafine particles had a fairly uniform structure and a mean particle size of 10 nm from the TEM measurement. The ultrafine powder possessed good soft magnetic properties and superparamagnetic behavior. (C) 1999 Published by Elsevier Science B.V. All rights reserved.