Time-resolved cathodoluminescence and photoluminescence of nanoscale oxides

L. Grigorjeva, D. Millers, A. Kalinko, V. Pankratov, K. Smits

Abstract
The nanostructured oxide materials such as ZnO, ZrO2, and Y3Al5O12 (YAG) are perspective materials for transparent scintillating and/or
laser ceramics. The luminescence properties of single crystals, nanopowders and ceramic were compared. Nominally pure and rare-earth doped
nanopowders and ceramics have been studied by means of time-resolved luminescence spectroscopy.
The fast blue luminescence band was studied in ZnO ceramics sintering from different raw materials.
The luminescence centres of ZrO2:Y were compared in a single crystal, ceramic and nanopowder.
It is shown that ceramic sintering parameters have a strong influence on time-resolved luminescence characteristics in cerium-doped YAG.

Journal of The European Ceramic Society

doi:10.1016/j.jeurceramsoc.2008.03.037

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Advanced nanocrystalline ZrO2 for optical oxygen sensors

Janusz D. Fidelus and Witold Łojkowski, Donats Millers, Krisjanis Smits and Larisa Grigorjeva

Abstract It was shown that ZrO2 nanopowders and
nanoceramics can be used as an optical oxygen sensor,
where the luminescence signal is proportional to the
partial oxygen pressure in gases. The nanopowders were
obtained in a hydrothermal microwave driven process
followed by annealing at 750oC. Nanoceramics were
obtained by sintering at pressures up to 6 GPa and at
250oC so that grain growth did not occur. Luminescence
of both materials depends linearly on the oxygen content
in nitrogen-oxygen mixtures for 2.1% – 25 vol% oxygen
content. For luminescence excitation using a laser beam,
the luminescence intensity decreases as oxygen pressure
increases. For excitation with an electron beam, the
opposite effect is observed – the lower the oxygen
pressure, the lower the luminescence signal. The
experimental results are explained in terms of
luminescence centers being distorted lattice sites close to
vacancies.

Proceedings of IEEE Sensors 2009

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