| Autor: |
Razvan Stefan, O. Raita, Eugen Culea, Petru Pascuta, Adriana Florina Popa, Emil Indrea |
| Rok vydání: |
2012 |
| Předmět: |
|
| Zdroj: |
Journal of Physics and Chemistry of Solids. 73:221-226 |
| ISSN: |
0022-3697 |
| DOI: |
10.1016/j.jpcs.2011.10.039 |
| Popis: |
Glasses in the system xFe2O3·(100−x) [45ZnO·55B2O3] (0≤x≤10 mol%) have been prepared by melting at 1200 °C and rapidly cooling at room temperature. The obtained samples were submitted to an additional thermal treatment at 570 °C for 12 h in order to relax the glass structure as well as to improve the local order. The as cast and heat treated samples were investigated using X-ray diffraction (XRD) and electron paramagnetic resonance (EPR) measurements. The XRD patterns of all the studied samples show their vitreous nature. Structural modifications occurring in the heat treated samples compared to the untreated ones have been pointed out. EPR spectra of untreated and heat treated samples revealed resonance absorptions centered at g≈2.0, g≈4.3 and g≈6.4. The compositional variation of the line intensity and linewidth of the absorptions from g≈4.3 and g≈2.0 have been interpreted in terms of the variation in the concentration of the Fe3+ ions and the interaction between the iron ions. The EPR spectra of the untreated samples containing 5 mol% Fe2O3 have been studied at different temperatures (110–290 K). The line intensity of the resonance signals decreases with increase in temperature whereas the linewidth is found to be independent of temperature. It was also found that the temperature variation of reciprocal line intensity obeys the Boltzmann law. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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