Reaction mechanisms of strontium ferrites synthesis

摘要

The reactions between strontium and iron nitrates have been studied in an open atmosphere system using three different molar ratios, 1:1 (I), 1:2 (II) and 2:1(III) at different temperatures as pointed out from the DTA data. The reaction mechanism was discussed based on the chemical composition characterized by means of thermal analysis, X-ray diffraction patterns, infrared spectra and magnetic susceptibility. It was found that the reaction products depend on both temperature of reaction and the ratio between reactants. The reaction products were found to be composed of a variety of iron compounds that possess different valences: SrFeO_(2.86), SrFeO_(2.97), SrFe_2O_4, SrFe_(12)O_(19), Sr_2Fe_2O_5 and Sr_7Fe_(10)O_(22) in addition to some accessory reaction products namely alpha-Fe_2O_3 and FeO(OH).