Combustion synthesis of Ni-Zn ferrite powder - influence of oxygen balance value

In this study, Ni0.5Zn0.5FC2O4 powder was synthesized via an exothermic reaction between nitrates [Ni(NO3)(2).6H(2)O, Zn(NO3)(2).6H(2)O, Fe(NO3)(3).9H(2)O, and NH4NO3] and glycine [NH2CH2COOH]. By adjusting the glycine-to-nitrates ratio, the oxygen balance (OB) values of the reactant mixtures can be varied in which the combustion phenomena is altered and thereby the as-synthesized products with different characteristics are obtained. An interpretation based on the measurement of maximum combustion temperature (T-c) and the amounts of gas evolved during reaction for various OB values has been proposed regarding the nature of combustion and its correlation with the characteristics of as-synthesized products. After instrumental analyses, it is shown that the as-synthesized powders are nanoscale crystallites with a large specific surface area and they inherit a superparamagnetic behavior. (C) 2004 Elsevier Inc. All rights reserved.