ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 38, Number 2
JKCSEZ 38(2)
April 20, 1994 

Ultrafine cobalt-substituted iron oxide particles were prepared by the thermal decomposition and oxidation of the new organometallic precursor, CoxFe1-x(N2H3COO)2(N2H4)2 (x = 0, 0.01, 0.02, 0.03, 0.05, 0.10, 1.00). The organometallic precursors were synthesized by the reaction of Co(Ⅱ) and Fe(Ⅱ) ion in a mole ratio of x : 1-x with hydrazinocarboxylic acid, and characterized by quantitative analysis, elemental analysis and infrared spectroscopy. The mechanistic study on the thermal decomposition of the organometallic precursors was performed by TG-DTG and DSC. The cobalt-substituted iron oxide particles were obtained by the heat treatment of the precursors at 350℃ and 450℃ for six hours in air. The prepared iron oxide was found to have two phases such as γ-Fe2O3 and a mixture of γ-Fe2O3 and α-Fe2O3 at 350℃ and 450℃ respectively. The particle shape was equiaxial and the particle size was less than 0.05 μm. The coercivity and squareness of the cobalt substituted iron oxide particles increased with increasing cobalt content. Both coercivity and squareness showed higher values at 450℃