| Autor: |
N. M. Shash, F. A. Afifi, M. H. Maklad, M.G. El-Shaarawy, Mohamed M. Rashad |
| Rok vydání: |
2015 |
| Předmět: |
|
| Zdroj: |
Journal of Magnetism and Magnetic Materials. 374:495-501 |
| ISSN: |
0304-8853 |
| DOI: |
10.1016/j.jmmm.2014.08.090 |
| Popis: |
Nanocrystalline lithium ferrite LiFe 5 O 8 powders were synthesized by the sol gel auto-combustion method from the corresponding metal nitrates using urea as a fuel. DTA results showed that the LiFe 5 O 8 phase started to form at temperature around 385 °C. X-ray diffraction analysis indicates that all compositions were formed in a single-phase cubic spinel structure at different annealing temperatures from 400 to 800 °C for 2 h. The lattice parameter was found to decrease whereas the particle size was increased with annealing temperature. The frequency exponent “ s ” of lithium ferrite lies in the range 0.5≤ s ≤1, which confirmed the electron hopping between Fe 2+ and Fe 3+ ions. The electron mobility in LiFe 5 O 8 samples ranged from 0.05 to 0.29 eV, which clearly indicated that the present lithium ferrites have semiconductor-like behavior. The saturation magnetization was increased on increasing the annealing temperature up to 800 °C. High saturation magnetization ( Ms =51.9 emu/g) was achieved for the ferrite powders produced at annealing temperature 800 °C for 2 h. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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