Enhanced optical properties of yttrium aluminum garnet with the yttrium vanadate impurity phase

Yttrium aluminum garnet doped with europium with an additional impurity phase of yttrium vanadate doped europium has been prepared in different ways: synthesized by a sol-gel route and mechanically mixed in a mortar. The obtained samples were characterized by X-ray diffraction analysis, and scanning electron microscopy. Photoluminescence spectra were recorded to understand the role of the impurity phase in the garnet's optical properties. The impurity phase showed a significant contribution to the optical properties of Y3Al5O12:1%Eu. --//-- Monika Skruodiene, Ruta Juodvalkyte, Meldra Kemere, Rimantas Ramanauskas, Anatolijs Sarakovskis, Ramunas Skaudzius, Enhanced optical properties of yttrium aluminum garnet with the yttrium vanadate impurity phase, Heliyon, Volume 8, Issue 11, 2022, e11386, ISSN 2405-8440, https://doi.org/10.1016/j.heliyon.2022.e11386. (https://www.sciencedirect.com/science/article/pii/S2405844022026743). Published under the CC BY-NC-ND licence.ERDF [1.1.1.2/VIAA/3/19/480]; the Institute of Solid State Physics, University of Latvia (Latvia), as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Frame-work Programme H2020-WIDESPREAD-01-2016-2017-Teaming Phase2 under grant agreement No. 739508, project CAMART

Sol-gel assisted molten-salt synthesis of novel single phase Y3–2xCa2xTaxAl5−xO12:1%Eu garnet structure phosphors

Strong absorption and emission are the key the features of any phosphor. The results obtained during this study demonstrate the difficulty of the incorporation of tantalum ions into the garnet structure and reveal that only the combination of Sol-Gel synthesis method together with Molten-Salt technique enable to obtain a single-phase cubic garnet structure. Note that, the Sol-Gel synthesis assisted by further processing by Molten-Salt technique can be a potentially new way of material preparation reported in literature. This work also proves that this combination of synthesis methods is much more capable of incorporating ions with large ionic radii into the garnet structure as compared to traditional Sol-Gel method. Moreover, samples synthesized using this new technique exhibit 30% higher emission intensities as compared to the ones prepared by the original Sol-Gel method, while also reducing the needed sintering temperature by 200 °C. To the best of our knowledge, the modification of yttrium aluminum garnet (Y3Al5O12, YAG) by co-doping it with Ca2+ and Ta5+ ions by Sol-Gel assisted Molten-Salt route has been investigated for the first time. --//-- Monika Skruodiene, Ruta Juodvalkyte, Greta Inkrataite, Andrius Pakalniskis, Rimantas Ramanauskas, Anatolijs Sarakovskis, Ramunas Skaudzius, Sol-gel assisted molten-salt synthesis of novel single phase Y3–2xCa2xTaxAl5−xO12:1%Eu garnet structure phosphors, Journal of Alloys and Compounds, Volume 890, 2022, 161889, ISSN 0925-8388, https://doi.org/10.1016/j.jallcom.2021.161889. Article published under the CC BY license.The work of Monika Skruodiene is supported by ERDF PostDoc project No. 1.1.1.2/VIAA/3/19/480. Institute of Solid State Physics, University of Latvia has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2

Synthesis and Investigation of Novel Optical Active SiO₂ Glasses with Entrapped YAG:Ce Synthesized via Sol–Gel Method

We present a crack-free optically active SiO2 glass-composite material containing YAG:Ce synthesized via a modified sol–gel technique. A glass-composite material consisting of yttrium aluminum garnet doped with Ce3+ (YAG:Ce) was entrapped into a SiO2 xerogel. This composite material was prepared using a sol–gel technique with modified gelation and a drying process to obtain crack-free optically active SiO2 glass. The concentration of the YAG:Ce was from 0.5 to 2.0 wt%. All synthesized samples were characterized via X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, confirming their exceptional quality and structural integrity. The luminescence properties of the obtained materials were studied. Overall, the prepared samples’ excellent structural and optical quality makes them great candidates for further investigation, or even potential practical application. Furthermore, boron-doped YAG:Ce glass was synthesized for the first time

Self-Healing Properties of Cerium-Modified Molybdate Conversion Coating on Steel

Environmentally friendly alternatives to chromium—phosphate/molybdate and cerium-modified phosphate/molybdate conversion coatings—were deposited on a carbon steel surface. Different surface analytic techniques were applied to obtain complementary information on the composition, element distribution morphology and inner structure of the coatings in order to establish the relationship between coating properties and corrosion performance. The higher protective and stronger self-healing abilities were found for phosphate/molybdate/cerium conversion coating deposited in a sulphate-containing solution. The protective barrier strength was found to be related with certain aspects of the coating morphology such like homogeneous distribution of fine crystallites and, hence, lower number of structural defects. The self-healing ability depended on both, the composition (higher amount of Ce(IV)) and micro-structural characteristics, such as defectiveness, of the conversion layer