Mössbauer study on thermal decomposition of ammonium tris (malonato) ferrate (III) tetrahydrate

Abstract

Thermal decomposition of ammonium tris (malonato) ferrate (III) tetrahydrate, i. e. (NH4)3[Fe(CH2C2O4)3]·4H2O has been studied up to 973 K in static air atmosphere employing Mossbauer and infrared spectroscopies, and non-isothermal techniques (TG, DTG, DTA). The anhydrous complex decomposes into an iron (II) intermediate at 453 K. The iron (II) species on further heating is reoxidized to α-Fe2O3 as the final thermolysis product. An increase in particle size of α-Fe2O3 with increasing decomposition temperature has been observed. The results are compared with the analogous oxalate complex.