Abstract
The thermal decomposition of ferrous oxalate dihydrate FeC2O4.2H2O, has been investigated using thermogravimetric (TG), differential thermogravimetric (DTG), differential thermal analysis (DTA), X-ray diffraction and infra-red spectroscopic techniques.
The DTA data obtained in air consist of an endothermic dehydration peak at ∼ 190‡ C and two exothermic peaks at ∼ 245 and ∼ 360‡ C. The first exotherm corresponds to the primary oxidative decomposition while the second one seems to be due to a structural transformation from a disordered or non-crystalline to a crystalline state ofα-Fe2O3. Similar experiments carried out using a nitrogen atmosphere show an endothermic peak ∼ 190‡ C followed immediately by an exothermic peak at 240‡ C. The final product of this decomposition has been identified as Fe3O4.
The oxalate dihydrate containing traces of moisture decomposes in air under the ambient of its own gaseous products at ∼ 300‡ C to giveγ-Fe2O3. This compound has been characterized by X-ray diffraction and magnetic hysteresis measurements.
Similar content being viewed by others
References
P. D. Peshev andO. Tsyrnorechki,Chem. Abstracts 55 (1961) 9137h.
O. Tsyrnorechki andIV. Arshinkov,ibid 55 (1961) 9138b.
J. Gopalakrishnan, private communication.
S. C. Bevan andR. A. Brown,J. Inorg. Nuclear Chem. 28 (1966) 387.
D. Broadbent, J. Dollimore andD. Dollimore,J. Chem. Soc. A (1967) 451.
S. D. Likhite, C. Radhakrishnamurthy andP. W. Sahasrabudhe,Rev. Sci. Instrum. 36 (1965) 1558.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Rao, V., Shashimohan, A.L. & Biswas, A.B. Studies on the formation of γ-Fe2O3 (maghemite) by thermal decomposition of ferrous oxalate dihydrate. J Mater Sci 9, 430–433 (1974). https://doi.org/10.1007/BF00737843
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00737843