Preparation of magnesium ferrite from the thermolysis of magnesium tris(maleato)ferrate (III)

摘要

Thermolysis of magnesium tris(maleato)ferrate(III) has been studied from ambient to 873 K in static air atmosphere employing TG, DTG, DTA, XRD, Mossbauer and infrared spectroscopic techniques. The precursor decomposes to an iron(II) intermediate species along with magnesium maleate at 443 K. The iron(II) species then undergoes oxidative decomposition to give #alpha#-Fe_2O_3 at 553 K. At higher temperature, magnesium maleat decomposes directly to magnesium oxide, MgO, which undergoes a solid state reaction with #alpha#-Fe_2O_3 to yield magnesium ferrite (MgFe_2O_4) at 700 K, a temperature which is lower than for the ceramic method. The results have been compared with those of the oxalate precursor.