Preparation of luminescent nanocrystals started from amorphous zirconia prepared by sol-gel technique

This article reports the experimental results concerning the thermoluminescent (TL) and photoluminescent (PL) characteristics of nanopolicrystalline zirconium oxide (ZrO₂) powder prepared by the conventional sol-gel method. Transmission electron miscroscopy and X-ray diffraction techniques were used for morphological and structural characterization of the compound. Thermal annealing processes for the precipitates were studied. It is observed that the crystalline structure and the crystallinity of the powders depend on the annealing temperature. For temperatures higher than 1000 °C, the material presents the monoclinic phase with an average crystalline grain size of 40 nm. The TL glow curve of the undoped ZrO₂ has a simple structure with two prominent peaks at around 160 and 270 °C, with a small shoulder in the second peak. TL response of the ZrO₂ as a function of beta-irradiation showed a wide range of the dose. Fading and reusability of phosphor were also studied. Measurements on PL show excitation and emission spectra.