Abstract
Gel-combustion synthesis was applied for CoZ-ferrite (Ba3Co2Fe24O41) fine powder. Either citric acid or glycine was added to the mixed aqueous solution of Ba(NO3)2, Co(NO3)2•6H2O and Fe(acac)3. The product gel was ignited at 150oC and then fired again up to a temperature of 500oC to 1200oC. The ignited and fired products were respectively a mixture of CoFe2O4 and Ba(NO3)2 and that of CoZ-, CoY-, M-ferrites and BaFe2O4 when citric acid was used as a gelling agent. The ignited product was a mixture of CoFe2O4 and BaFe2O4 because higher temperature was attained in the ignition of glycine gel than citric acid gel. CoZ-ferrite fine powder was obtained in firing the ignited product at 1000oC. Crystallite and average particle sizes were 45 and 200nm, respectively. Saturation magnetization was 250G and coercivity was 0.6 to 0.9kOe.
