Phase Formation in the Systems ( )-FeOOH–M(OH)2–H2O (M = Mn, Co, Zn)

Abstract

The sequence of chemical transformations induced in the systems α(δ)-FeOOH–M(OH)2–H2O (M = Mn, Co, Zn) by heat treatment in the range 125–200°C is studied. The results demonstrate that the kinetics of M(II) ferrite formation, the chemical and phase compositions of the product, and its particle size distribution depend on the heat-treatment temperature, the pH of the suspension (or NaOH concentration), the FeOOH polymorph used as a starting reagent, and the starting-mixture composition.