Investigation of temperature dependence of Raman and photoluminescence analysis of YBa2Cu3O7 (YBCO) doped with SiO2 nanoparticles
We report the effect of SiO2 nanoparticles (12 nm) in YBa2Cu3O7 (YBCO) matrix. The samples YBCO and SiO2+YBCO are fabricated by a conventional solid-state reaction method, in ambiance conditions. We analyze these samples using X-ray diffraction (XRD), resonant Raman, environmental scanni...
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| 格式: | 文件 |
| 语言: | English |
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International Institute for the Science of Sintering, Beograd
2018-01-01
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| 丛编: | Science of Sintering |
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| 在线阅读: | http://www.doiserbia.nb.rs/img/doi/0350-820X/2018/0350-820X1801063A.pdf |
| 总结: | We report the effect of SiO2 nanoparticles (12 nm) in YBa2Cu3O7 (YBCO)
matrix. The samples YBCO and SiO2+YBCO are fabricated by a conventional
solid-state reaction method, in ambiance conditions. We analyze these
samples using X-ray diffraction (XRD), resonant Raman, environmental
scanning electron microscopy (ESEM), and Photoluminescence (PL) as a
function of temperature in the range from 77 to 837 K. The XRD confirm that
the doped YBCO still displays a perovskite structure with the orthorhombic
Pmmm phase. The Rietveld refinement confirms that SiO2 nanoparticles induce
not only a strong effect on the oxygen’s O(5) and O(8) positions but also an
elongation of the unit cell along the c-axis. The PL intensity of pure YBCO
is more intense than the doped one that is mainly composed of two bands
located at 2.4 eV and 1.88 eV. We simulate the PL intensity with temperature
using the Bose-Einstein model with two activation energies corresponding to
some specific vibration mode energies. The simulation reveals that the
exchange energy between different levels in pure and doped YBCO is conducted
by only two vibrations modes that are strongly linked to the oxygen and
copper atoms in the YBCO matrix. We determine the evolution of Raman mode
frequencies at 340 and 500 cm−1 with temperature using the Lorentzian
function at q = 0 of the Balkanski model. |
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| ISSN: | 0350-820X 1820-7413 |