Structural features of hydrate forms of iron(III) oxalate

The existence of hydrate forms of iron(III) oxalate, which noticeably differ from each other in the Mössbauer spectral parameters (isomer shift and quadrupole splitting), is detected. In the assumption of the formation of phases with different structural characteristics, the samples of compound under study are examined by the powder X-ray diffraction analysis (including the application of synchrotron radiation), Mössbauer and IR spectroscopy. It is shown that the phase characterized by new values of the Mössbauer parameters has its own IR spectrum and it is X-ray amorphous and metastable.