Metal-hydrazine complexes as precursors to oxide materials

Abstract

Metal-hydrazine complexes, [M(N₂H₄) _n ]²⁻ (M=Mn, Fe, Co, Ni, Zn and Cd,n=2 or 3) with different anions like sulphate, sulphite, acetate, formate, oxalate, hydrazinocarboxylate, nitrate and perchlorate have been investigated as precursors to oxide materials. The thermal reactivity of these complexes changes dramatically with the anion, e.g. sulphate, sulphite, acetate and formate complexes—decompose; oxalate and hydrazinocarboxylates—deflagerate and nitrate and perchiorate complexes—detonate. The deflagerating nature of the metal-hydrazine oxalates and hydrazinocarboxylates has been employed in the combustion synthesis of fine particle γ-Fe₂O₃, Fe₃O₄, ferrites and cobaltites at low temperature.