Preparation of NiFe₂O₄ powder by spray pyrolysis of nitrate aerosols in NH₃

Abstract

To avoid the formation of hollow spheres during spray pyrolysis, NH3 was employed to change the mechanism of forming NiFe2O4 from aerosols, containing Ni(II) and Fe(III) nitrates in the required stoichiometric ratio. Nearly spherical, solid submicron NiFe2O4 particles with narrow size distribution were produced in one step using a dilute aqueous solution at pyrolysis temperatures as low as 823 K. However, higher pyrolysis temperatures (≥1023 K) reduced the oxides to metallic alloy of Ni and Fe due to dissociation of NH3. The forming steps and possible reaction mechanisms for aerosol droplets involved in the process were discussed.

Synthesis and characterization of NiFe2O4 nanopowders via spray pyrolysis

“…15) In addition, Yu and Gadalla prepared NiFe2O4 powders by spray pyrolysis and investigated the effects of operating parameters on the quality of the aerosol product. 16) In this study, NiFe2O4 powders with large-sized, hollow, and thin wall structures were directly prepared by spray pyrolysis from a spray solution containing an organic additive. After being post-treated at high temperatures, these powders converted into nanosized NiFe2O4 powders.…”

Structure and magnetic properties of Mg0.35Cu0.2Zn0.45Fe2O4 ferrite synthesized by co-precipitation method

“…[10][11][12] There are many methods that can be used to obtain the ferrite nanoparticles. [13][14][15][16][17] Of all these techniques, chemical co-precipitation seems to be the most convenient for the synthesis of nanoparticles because of its simplicity and better control over crystallite size and other properties of the materials. Although MgCuZn ferrite has been synthesized by chemical co-precipitation, 18 the systematic investigation on soft magnetic properties is still needed.…”

Direct and facile synthesis of Li–Sr–Zn ferrites via low temperature solution combustion route

“…Ferrite materials are also used in fabrication of magnetic cores for disk recordings and digital tapes [4,5], in levitated railway systems as repulsive suspension, magnetic refrigeration systems, ferrofluids and catalysis [6,7], in electromagnetic applications as ferrites can absorb electromagnetic radiation in microwave region [8]. Different techniques such as wet chemical methods [9][10][11][12][13], spray drying [14], and hydrothermal methods [15] have been employed, which lead to the formation of nanoscale ferrite particles. The conventional ceramic method which includes preparation of ferrites at high temperature results in loss of fine particle nature.…”