Low-Temperature Combustion Synthesis and Properties of CoFe2O4 and CoGa x Fe2 – xO4 (x = 0.05, 0.10) Nanoparticles

Abstract

CoFe2O4 and CoGa x Fe2 – xO4 (x = 0.05, 0.10) nanopowders have been synthesized via low-temperature combustion using cobalt, gallium, and iron complexes of malonic acid dihydrazide as precursors. Presynthesized precursors have been shown to decompose at temperatures as low as 250–300°C to form mineral residues with an amorphous structure after the combustion of the organic component. Heat treatment above 700°C leads to an onset of crystallization. The formation of the spinel structure reaches completion at 1200°C. The average particle size of the CoFe2O4, CoGa0.05Fe1.95O4, and CoGa0.1Fe1.9O4 powders has been determined to be 476, 435, and 317 nm, respectively. The electrical resistance and dielectric permittivity of the samples have been measured as functions of annealing temperature.