MOSSBAUER-EFFECT STUDY OF THE BETA-FEOOH TO ALPHA-FE2O3 PHASE-TRANSFORMATION

Authors
KNESE K WARTEWIG P MICHALK C FISCHER S
Citation
K. Knese et al., MOSSBAUER-EFFECT STUDY OF THE BETA-FEOOH TO ALPHA-FE2O3 PHASE-TRANSFORMATION, Hyperfine interactions, 94(1-4), 1994, pp. 1999-2004
Citations number
13
Categorie Soggetti
Physics, Atomic, Molecular & Chemical","Physics, Nuclear","Physics, Condensed Matter
Journal title
Hyperfine interactions → ACNP
ISSN journal
03043843
Volume
94
Issue
1-4
Year of publication
1994
Pages
1999 - 2004
Database
ISI
SICI code
0304-3843(1994)94:1-4<1999:MSOTBT>2.0.ZU;2-J
Abstract
beta-FeOOH was precipitated from a chloride solution. Mossbauer spectr a were taken at room temperature (RT) and at 4.2 K in zero field and i n external magnetic fields. Samples aged for successively longer time periods were studied. They contain alpha-FeOOH and alpha-Fe2O3, the Mo ssbauer spectra of which show superparamagnetic behavior. The transfor mation into alpha-Fe2O3 is already induced by aging in the mother solu tion at 100 degrees C. A final heat treatment at 350 degrees C leads t o the complete transformation into alpha-Fe2O3 and to an increase of t he crystallite size.