Bs. Randhawa et K. Sweety, Preparation of sodium ferrite from the thermolysis of sodium tris(maleato/fumarato)ferrates(III), J RAD NUCL, 238(1-2), 1998, pp. 141-144
Thermal decomposition of sodium tris(maIeato)ferrate(III) hexahydrate, Na-3
[Fe(C4H2O4)(3)]. 6H(2)O and sodium tris(fumarato)ferrate(III) heptahydrate,
Na-3[Fe(C4H2O4)(3)]. 7H(2)O has been studied upto 973 K in static air atmo
sphere employing TG, DTG, DSC, XRD, Mossbauer and infrared spectroscopic te
chniques. Dehydration of the maleate complex is complete at 455 K and the a
nhydrous complex immediately undergoes decomposition till alpha-Fe2O3 and s
odium carbonate are formed at 618 K. In the final stage of remixing of cati
ons, a solid state reaction between alpha-Fe2O3 and sodium carbonate leads
to the formation of alpha-NaFeO2 at a temperature (773 K) much lower than f
or ceramic method. Almost similar mode of decomposition has been observed f
or the fumarate complex. A comparison of the thermal stability shows that t
he fumarate precursor decomposes at a higher temperature than the maleate c
omplex due to the trans geometry of the former.