Study of iron oxides obtained by decomposition of an organic precursor

Iron oxide powders were obtained by the isothermal decomposition of ferric citrate in an oxygen atmosphere at different temperatures. Throughout the e xperiments, the product of decomposition was a mixture of maghemite (gamma- Fe2O3) and hematite (alpha-Fe2O3) with different relative proportions and p article size distributions. After TGA and DTA measurements, a decomposition temperature of 300 degrees C was chosen, and a maximum specific saturation magnetization of about 40 emu/g was obtained. Most of the product particle s were less than 1 mu m in size, including a superparamagnetic fraction, as evidenced by Mossbauer spectroscopy. (C) 1999 Elsevier Science B.V. All ri ghts reserved.