Synthesis of acicular α-FeOOH particles at a very high pH

The acicular alpha-FeOOH particles were synthesized from FeCl3 solutions at a very high pH using tetramethylammonium hydroxide as a precipitating agent. Samples were characterized by X-ray powder diffraction, FT-IR spectroscopy and transmission electron microscopy, alpha-FeOOH precipitated as a single phase from room temperature to 160 degreesC in a broad aging time interval. The ratio of the length to the width of alpha-FeOOH particles depended on the temperature and concentration of the starting FeCl3 solution, Multidomainic character of alpha-FeOOH particles gradually decreased with an increase in the temperature and time of aging. (C) 2002 Elsevier Science B.V. All rights reserved.