Surface Conditions and Plasticity of the Body of α-Fe₂O₃ Powder

Abstract

α-Fe₂O₃ fine powders prepared by oxydation of Fe₃O₄ and by dehydration of α-FeOOH show different plastic properties of the body. The dependence of the plastic properies on the surface conditions and pore volumes of the α-Fe₂O₃ fine powders were examined by BET method (N₂ gas) and DSC. All values of the plastic properties of the body, the surface area and pore volume of α-Fe₂O₃ powder prepared by dehydration of α-FeOOH are higher than those of the α-Fe₂O₃ powder prepared by oxidation of Fe₃O₄. The water molecules absorbed in pores with radius within 20A on α-Fe₂O₃ particle can be estimated as condensed capillary water and/or non-frozen water.