Vallina, B, Rodriguez-Blanco, JD, Benning, LG et al. (2 more authors) (2014) Enhanced magnetic coercivity of α-FeO obtained from carbonated 2-line ferrihydrite. Journal of Nanoparticle Research, 16 (3). 2322. ISSN 1388-0764
Abstract
We report the physical properties of α-FeO (hematite), synthesized by dry-heating (350-1,000°C) of a new, poorly ordered iron oxyhydroxide precursor compound that we name carbonated 2-line ferrihydrite. This precursor was characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, electron microscopy, and thermogravimetric analysis, whereas the α-FeO was studied with X-ray diffraction, scanning and transmission electron microscopy, and magnetic techniques. α-FeO synthesized at 350°C consisted of single-nanocrystal particles (length × width 20 ± 6 nm (L) × 15 ± 4 nm (W)), which at room temperature exhibited very narrow hysteresis loops of low coercivities (<300 Oe). However, α-FeO synthesized at higher temperatures (1,000°C) was composed of larger nanocrystalline particle aggregates (352 ± 109 nm (L) × 277 ± 103 nm (W)) that also showed wide-open hysteresis loops of high magnetic coercivities (∼5 kOe). We suggest that these synthesis-temperature-dependent coercivity values are a consequence of the subparticle structure induced by the different particle and crystallite size growth rates at increasing annealing temperature.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2014, Springer. This is an author produced version of a paper published in Journal of Nanoparticle Research. Uploaded in accordance with the publisher's self-archiving policy. The final publication is available at Springer via http://dx.doi.org/10.1007/s11051-014-2322-5 |
Keywords: | Hematite; ferrihydrite; high coercivity; carbonate; microstructure |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) > Institute for Materials Research (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 09 May 2014 15:21 |
Last Modified: | 16 Nov 2016 15:19 |
Published Version: | http://dx.doi.org/10.1007/s11051-014-2322-5 |
Status: | Published |
Publisher: | Springer |
Identification Number: | 10.1007/s11051-014-2322-5 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:78765 |