Thermal decomposition of barium ferrate(VI): Mechanism and formation of FeIV intermediate and nanocrystalline Fe2O3 and ferrite

Libor Machala, Virender K. Sharma, Ernö Kuzmann, Zoltán Homonnay, Jan Filip, Radina P. Kralchevska

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Simple high-valent iron-oxo species, ferrate(VI) (FeVIO42-, Fe(VI)) has applications in energy storage, organic synthesis, and water purification. Of the various salts of Fe(VI), barium ferrate(VI) (BaFeO4) has also a great potential as a battery material. This paper presents the thermal decomposition of BaFeO4 in static air and nitrogen atmosphere, monitored by combination of thermal analysis, Mössbauer spectroscopy, X-ray powder diffraction, and electron-microscopic techniques. The formation of FeIV species in the form of BaFeO3 was found to be the primary decomposition product of BaFeO4 at temperature around 190 °C under both studied atmospheres. BaFeO3 was unstable in air reacting with CO2 to form barium carbonate and speromagnetic amorphous iron(III) oxide nanoparticles (<5 nm). Above 600 °C, a solid state reaction between BaCO3 and Fe2O3 occurred, leading to the formation of barium ferrite nanoparticles, BaFe2O4 (20-100 nm).

Original languageEnglish
Pages (from-to)73-79
Number of pages7
JournalJournal of Alloys and Compounds
Volume668
DOIs
Publication statusPublished - May 25 2016

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Keywords

  • Hyperfine interactions
  • Mössbauer spectroscopy
  • Solid state reactions
  • Thermal analysis
  • X-ray diffraction

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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