Thermal decomposition of iron(VI) oxides, K{sub 2}FeO{sub 4} and BaFeO{sub 4}, in an inert atmosphere
- Institute of General and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellert ter 4, H-1521 Budapest (Hungary)
- Department of Physical Chemistry, Palacky University, Svobody 26, 771 46 Olomouc (Czech Republic)
- Department of Nuclear Chemistry and MTA-ELTE Research Group on the Application for Nuclear Techniques in Structural Chemistry, Eoetvoes Lorand University, H-1117 Budapest, Pazmany P. s. 1/A, Budapest (Hungary)
- Chemistry Department, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901 (United States)
The thermal decomposition of solid samples of iron(VI) oxides, K{sub 2}FeO{sub 4}.0.088 H{sub 2}O (1) and BaFeO{sub 4}.0.25H{sub 2}O (2) in inert atmosphere has been examined using simultaneous thermogravimetry and differential thermal analysis (TG/DTA), in combination with in situ analysis of the evolved gases by online coupled mass spectrometer (EGA-MS). The final decomposition products were characterized by {sup 57}Fe Moessbauer spectroscopy. Water molecules were released first, followed by a distinct decomposition step with endothermic DTA peak of 1 and 2 at 273 and 248 deg. C, respectively, corresponding to the evolution of molecular oxygen as confirmed by EGA-MS. The released amounts of O{sub 2} were determined as 0.42 and 0.52 mol pro formula of 1 and 2, respectively. The decomposition product of K{sub 2}FeO{sub 4} at 250 deg. C was determined as Fe(III) species in the form of KFeO{sub 2}. Formation of an amorphous mixture of superoxide, peroxide, and oxide of potassium may be other products of the thermal conversion of iron(VI) oxide 1 to account for less than expected released oxygen. The thermogravimetric and Moessbauer data suggest that barium iron perovskite with the intermediate valence state of iron (between III and IV) was the product of thermal decomposition of iron(VI) oxide 2.
- OSTI ID:
- 20785007
- Journal Information:
- Journal of Solid State Chemistry, Vol. 179, Issue 5; Other Information: DOI: 10.1016/j.jssc.2006.01.054; PII: S0022-4596(06)00068-5; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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