Nanoscience and Nanotechnology
p-ISSN: 2163-257X e-ISSN: 2163-2588
2013; 3(5): 130-134
doi:10.5923/j.nn.20130305.04
1Department of Physics, North Orissa University, Baripada 757003, Odisha, India
2Department of Physics, Salipur College, Salipur 754103, Odisha, India
Correspondence to: P. Mallick, Department of Physics, North Orissa University, Baripada 757003, Odisha, India.
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Effect of annealing on the microstructure, optical absorption properties of hematite (-Fe2O3) nanoparticles were studied. Crystallite size of
-Fe2O3 increased from ~ 34 to 44 nm with increasing annealing temperature from 500 to 700℃. Strain in the sample decreased with increasing annealing temperature. UV-visible characterization indicated the existence of both direct and indirect band gap in the samples. The samples annealed at all temperatures showed the direct band gap at ~ 2.67 eV. However, the indirect band gap increased from 1.6 to 1.94 eV when the annealing temperature increased from 500 to 600℃ and remained almost same for sample annealed at 700℃. The observed values of optical band gaps were in close agreement with the reported values. Our results indicated that the thermal annealing would give rise to well crystalline
-Fe2O3 nanoparticles with reduced strain.
Keywords: Iron Oxide, Nanoparticle, Annealing, Microstructure, Band Gap
Cite this paper: P. Mallick, B. N. Dash, X-ray Diffraction and UV-Visible Characterizations of α-Fe2O3 Nanoparticles Annealed at Different Temperature, Nanoscience and Nanotechnology, Vol. 3 No. 5, 2013, pp. 130-134. doi: 10.5923/j.nn.20130305.04.
![]() | Figure 1. XRD pattern of ![]() |
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![]() | Figure 2. Variation of crystallite size and strain for ![]() |
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![]() | Figure 3. Variation of absorption coefficient of ![]() |
![]() | Figure 4. Variation of ![]() ![]() ![]() |
![]() | Figure 5. Variation of ![]() ![]() ![]() |