| Autor: |
Khomenko, Olena V., Berezovskaya, Irina V., Poletaev, Nikolay I., Khlebnikova, Maria E., Efryushina, Ninel P., Dotsenko, Vladimir P. |
| Předmět: |
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| Zdroj: |
Journal of Chemistry & Technologies; 2022, Vol. 30 Issue 4, p537-546, 10p |
| Abstrakt: |
The Mn4+-doped α-Al2O3 with particle size of 70-600 nm was obtained by combustion method. Based on the results of luminescence measurements, the crystal-field strength (Dq) and Racah parameters (B, C) for Mn4+ in α-Al2O3 were determined using a pure electronic transition approach. The obtained values of Dq (1898 cm-1) and nephelauxetic parameter β1 (0.95) for Mn4+ ions in α-Al2O3 are consistent with those of Mn4+ in other oxide compounds. In particular, the Dq/B value of 2.77 indicates a strong crystal field environment of the Mn4+ ions in the α-Al2O3 lattice. A comparison with literature data for Cr3+ in α-Al2O3 was also carried out. The composites of general formula α-Al2O3: Mn4+, Mg2+/Gd3Al5O12:Ce3+ had been also obtained. It is shown that these materials demonstrate the intense broadband emission with maxima at about 585 and 678 nm. The broad band with a maximum at 585 nm is caused by the 5d→4f transitions of Ce3+ ions in Gd3Al5O12, whereas the band at 678 nm is caused by the Mn4+ 2Eg→4A2g transitions in α-Al2O3. The emission color changes from yellow to deep red with increasing content of α-Al2O3:Mn4+, Mg2+, and the luminescence quantum efficiency of the composites was found as high as 0.60. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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