Nano Size Crystals of Geothite, alpha-FeOOH: Synthesis and Thermal Transformation

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.01.032· OSTI ID:929869

Christensen, A; Jensen, T; Bahl, C; DiMasi, E

An aqueous suspension of amorphous iron(III) hydroxide was kept at room temperature (298 K) for 23 years. During this period of time the pH of the liquid phase changed from 4.3 to 2.85, and nano size crystals of goethite, {alpha}-FeOOH crystallized from the amorphous iron(III) hydroxide. Transmission electron microscopy (TEM) investigations, Moessbauer spectra, and powder X-ray diffraction using Co K{alpha} radiation showed that the only iron containing crystalline phase present in the recovered product was {alpha}-FeOOH. The size of these nano particles range from 10 to 100 nm measured by TEM. The thermal decomposition of {alpha}-FeOOH was investigated by time-resolved in situ synchrotron radiation powder X-ray diffraction and the data showed that the sample of {alpha}-FeOOH transformed to {alpha}-Fe{sub 2}O{sub 3} in the temperature range 444--584 K. A quantitative phase analysis shows the increase in scattered X-ray intensity from {alpha}-Fe{sub 2}O{sub 3} to follow the decrease of intensity from {alpha}-FeOOH in agreement with the topotactic phase transition.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 929869
• Report Number(s): BNL--80441-2008-JA
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 180; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
CRYSTALS
GOETHITE
HYDROXIDES
IRON
LIQUIDS
PARTICLE SIZE
PARTICLES
POWDERS
PYROLYSIS
RADIATIONS
SPECTRA
SUSPENSIONS
SYNCHROTRON RADIATION
SYNTHESIS
TEMPERATURE RANGE
TRANSFORMATIONS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
national synchrotron light source