This work focuses on the investigation of the reaction of alkali metal nitrates (LiNO(3), NaNO(3) and KNO(3)) with divalent metal salts (Cu(2+), Ni(2+) and Zn(2+)). Thermogravimetric analysis (TGA) was employed to study the kinetics and mechanisms of the above reactions, which led to the formation of the corresponding metal oxides. The reaction temperature was found to depend not only on the alkali metal but also on the metal salt (MCl(2) or M(NO(3))(2)) involved in the reaction. SEM observations show that the spectator ions present in the reacting medium have varying degrees of influence on the morphology of the powder; the growth directions, sizes and the homogeneity of their distribution, are modified. KNO(3) generates the most significant differences compared to LiNO(3) and NaNO(3). (C) 2004 Elsevier Ltd. All rights reserved.