In:
Science of Sintering, National Library of Serbia, Vol. 49, No. 2 ( 2017), p. 197-205
Kurzfassung:
Amorphous iron (III) oxide was obtained from clay, using ammonium hydroxide
as a precipitating agent. Influence of freeze drying under vacuum, as a
drying method, on particle size, chemical composition, and crystallinity of
obtained iron (III) oxide powder was investigated. After freeze drying,
precipitate was annealed in air at 500?C and 900?C. X-ray diffraction,
particle size analysis, scanning electron microscopy, energy dispersive
spectrometry, Fourier transform infrared spectroscopy, thermogravimetric and
differential thermal analysis were used to characterize obtained iron (III)
oxide powder. All of three powders obtained by freeze drying and annealing,
have low crystallinity and particles with irregular layered shape. Narrow
particle size distribution was given by an average diameter value of around
50 ?m for all observed powders. Iron-bearing materials like ?-Fe2O3 and ?-
Fe2O3 are obtained. Differential thermal analysis curve of obtained samples
showed endothermic reaction at 620?C which could be ascribed to phase
transition from cubic form ?- ? ?- Fe2O3. Thermal transformations of iron
(III) oxide, obtained from clay as a natural source, is suitable to explore
in the framework of materials chemistry, and opens the possibility to
synthesize materials based on Fe2O3 with specific magnetic behavior.
Materialart:
Online-Ressource
ISSN:
0350-820X
,
1820-7413
Sprache:
Englisch
Verlag:
National Library of Serbia
Publikationsdatum:
2017
ZDB Id:
2380860-3
