Formation of threadlike alpha-iron particles via hydrogen reduction of iron(III) hydroxychloride

Hydrogen reduction (400-780 degrees C) off iron hydroxychloride forming as thin crust on the surface of a drop of concentrated aqueous iron(III) chloride in an ammonia atmosphere yields alpha-iron consisting, according to electron microscopy and x-ray diffraction data, not only of irregularly shaped particles about 1 mu m across but also of long, threadlike particles about 1 mu m in diameter. The possible mechanisms of the observed texturing of metallic iron are discussed.