Abstract
β-Fe2O3 is the scarce polymorph of Fe 2O3 phases and is transformed easily into α-Fe 2O3 at high temperature. However, its crystal structure and the transformation mechanism to α-Fe2O3 are still unclear because of the difficulty in obtaining monophasic β-Fe 2O3 crystals. We established a synthesis method of the monophasic β-Fe2O3. It was synthesized by a two-step reaction: heating a mixture of Na2SO4 and Fe 2(SO4)3 in air at 250 C to form NaFe(SO 4)2, and subsequent heating the resultant phase with NaCl in air at 500 C. The crystal structure was refined to a bixbyite-type cubic structure (Ia3Ì...) with a = 9.4039(1) Å by the Rietveld method. Single crystalline β-Fe2O3 particles of approximately 1 μm in size were topotactically transformed into single α-Fe 2O3 crystals. Electron diffraction analysis revealed the crystallographic orientation relationships between β-Fe2O 3 and α-Fe2O3 to be [100] β//[0001]α, [010]β// [101Ì...0]α, and [001]β//[1Ì... 21Ì...0]α.
Original language | English |
---|---|
Pages (from-to) | 770-774 |
Number of pages | 5 |
Journal | Crystal Growth and Design |
Volume | 13 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 6 2013 |
ASJC Scopus subject areas
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics