Microstructure, Mössbauer, and Optical Characterizations of Nanocrystalline α-Fe2O3 Synthesized by Chemical Route
Joint Authors
Pradhan, Swapan Kumar
Chakrabarti, Mahuya
Sanyal, Dirtha
Banerjee, Abhijit
Patra, Soumitra
Pal, Mrinal
Source
Issue
Vol. 2011, Issue 2011 (31 Dec. 2011), pp.1-8, 8 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2011-10-12
Country of Publication
Egypt
No. of Pages
8
Main Subjects
Abstract EN
Nanocrystalline α-Fe2O3 of crystallite sizes ranging from 18 nm to 54 nm has been prepared by sol gel process and postannealing the powder up to 500C∘.
X-ray diffraction and transmission electron microscopy images have been used for determining the average crystallite sizes of the prepared samples.
The Rietveld analysis reveals that the “as-prepared” α-Fe2O3 powders are not completely stoichiometric, and significant (~20%) oxygen vacancies are noticed in the α-Fe2O3 lattice.
Oxygen atoms in as-prepared sample are significantly displaced and the lattice is heavily distorted.
With increasing annealing temperature the lattice approaches towards the stoichiometric oxygen concentration and perfect lattice configuration.
Mössbauer spectrum of the unannealed (as-prepared) α-Fe2O3 sample shows the superparamagnetic behavior at room temperature whereas all annealed samples show complete ferromagnetic behavior.
Optical band gaps of these nanocrystalline α-Fe2O3 samples have been measured from UV-Vis spectroscopy and found to decrease from 2.65 eV to 2.50 eV, like an n-type semiconductor, with increasing annealing temperature up to 500C∘.
American Psychological Association (APA)
Banerjee, Abhijit& Patra, Soumitra& Chakrabarti, Mahuya& Sanyal, Dirtha& Pal, Mrinal& Pradhan, Swapan Kumar. 2011. Microstructure, Mössbauer, and Optical Characterizations of Nanocrystalline α-Fe2O3 Synthesized by Chemical Route. ISRN Ceramics،Vol. 2011, no. 2011, pp.1-8.
https://search.emarefa.net/detail/BIM-469541
Modern Language Association (MLA)
Banerjee, Abhijit…[et al.]. Microstructure, Mössbauer, and Optical Characterizations of Nanocrystalline α-Fe2O3 Synthesized by Chemical Route. ISRN Ceramics No. 2011 (2011), pp.1-8.
https://search.emarefa.net/detail/BIM-469541
American Medical Association (AMA)
Banerjee, Abhijit& Patra, Soumitra& Chakrabarti, Mahuya& Sanyal, Dirtha& Pal, Mrinal& Pradhan, Swapan Kumar. Microstructure, Mössbauer, and Optical Characterizations of Nanocrystalline α-Fe2O3 Synthesized by Chemical Route. ISRN Ceramics. 2011. Vol. 2011, no. 2011, pp.1-8.
https://search.emarefa.net/detail/BIM-469541
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-469541