- Tytuł:
- Positron-annihilation and photoluminescence studies of nanostructured ZrO2
- Autorzy:
-
Fidelus, J. D.
Karbowski, A.
Mariazzi, S.
Brusa, R. S.
Karwasz, G. - Powiązania:
- https://bibliotekanauki.pl/articles/146313.pdf
- Data publikacji:
- 2010
- Wydawca:
- Instytut Chemii i Techniki Jądrowej
- Tematy:
-
positron annihilation
zirconia nanopowders
photoluminescence - Opis:
- In the present work, photoluminescence and Doppler broadening depth-resolved positron annihilation spectroscopy was performed on pure zirconia nanopowders. Zirconia nanopowders were grown by a hydrothermal microwave-driven process followed by annealing in oxygen atmosphere. Photoluminescence under 274 nm wavelength excitation from a 150 W high-pressure Xe exhibits similar spectra, in the region from 320 to 820 nm, although its intensity depends on the annealing. Positron annihilation Doppler-broadening spectra show low values of the normalized S-parameter, varying little with the depth, from 0.495 on the surface to 0.47-0.49 in bulk. Both high the annealing temperature and oxygen concentrations, lead to low bulk S-values. The ortho-positronium (o-Ps) fraction is about 10-11% for all samples on the surface, whereas it is reduced to 7-8% in the bulk for samples annealed at 700°C and 5-6% for samples annealed at 800°C. Both photoluminescence (PL) and positron studies show the presence of defects in all samples. The o-Ps signal suggests a high porosity of samples, particularly at a depth down to 10 nm.
- Źródło:
-
Nukleonika; 2010, 55, 1; 85-89
0029-5922
1508-5791 - Pojawia się w:
- Nukleonika
- Dostawca treści:
- Biblioteka Nauki
Artykuł