Thermal decomposition of iron(II) oxalate dihydrate in nitrogen using the Mössbauer effect

Abstract

Mössbauer spectra have been recorded of the solid products of the thermal decomposition of iron(II) oxalate dihydrate in an atmosphere of oxygen-free nitrogen at room temperature and at –196°. The isomer shift and quadrupole splitting of the anhydrous oxalate, which is produced above 170°, are reported. Decomposition occurs at 320° to magnetite and no trace of wüstite is observed. The second differential thermal analysis peak observed by other workers above 365° is paralleled by a simplification in the Mössbauer spectrum, which becomes similar to that of γ-Fe₂O₃.