Publication
Title
Mössbauer characterisation of the products resulting from hydrothermal treatments of nanosized goethite
Author
Abstract
Batches of poorly crystalline (GPC) and relatively well crystalline (GNL) goethite, alpha-FeOOH, powders have been suspended in a neutral aqueous medium and heated for three days in a pressure bomb at various temperatures between 100 and 300 degrees C. The parent acid resulting products have been characterised by thermogravimetric analyses, X-ray diffraction, BET surface-area measurements, transmission electron microscopy and Fe-57 Mossbauer spectroscopy. While the goethite particles of GNL are not affected by the treatments at up to 275 degrees C, those of GPC initially grow with increasing heating temperature up to similar to 200 degrees C and subsequently become smaller with further increase of the temperature. Above 250 degrees C, GPC produces a mixture of hematite, alpha-Fe2O3, and maghemite, gamma-Fe2O3. The presence of the latter phase is particularly obvious from the external-field Mossbauer spectrum. After being treated at 300 degrees C, both goethites have completely converted to hematite. The morphology of the parent goethite has no marked effect on the final hematite phase. (C)1999 Acta Metallurgica Inc.
Language
English
Source (journal)
Nanostructured materials. - New York
Publication
New York : 1999
ISSN
0965-9773
Volume/pages
11:4(1999), p. 493-504
ISI
000082298400008
Full text (Publishers DOI)
Full text (publishers version - intranet only)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 03.01.2013
Last edited 24.04.2017
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