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

Ferromagnetic-like behavior of Bi0.9La0.1FeO3-KBr nanocomposites

We studied magnetostatic response of the Bi0.9La0.1FeO3-KBr composites (BLFO-KBr) consisting of nanosized (about 100 nm) ferrite Bi0.9La0.1FeO3 (BLFO) conjugated with fine grinded ionic conducting KBr. When the fraction of KBr is rather small (less than 15 wt percent) the magnetic response of the composite is very weak and similar to that observed for the BLFO (pure KBr matrix without Bi1-xLaxFeO3 has no magnetic response as anticipated). However, when the fraction of KBr increases above 15percent, the magnetic response of the composite changes substantially and the field dependence of magnetization reveals ferromagnetic-like hysteresis loop with a remanent magnetization about 0.14 emu/g and coercive field about 1.8 Tesla (at room temperature). Nothing similar to the ferromagnetic-like hysteresis loop can be observed in BLFO ceramics, which magnetization quasi linearly increases with magnetic field. Different physical mechanisms were considered to explain the unusual experimental results for BLFO-KBr nanocomposites, but only those among them, which are highly sensitive to the interaction of antiferromagnetic Bi0.9La0.1FeO3 with ionic conductor KBr, can be relevant. An appropriate mechanism turned out to be ferro-magneto-ionic coupling.Comment: 24 pages, 4 figures in the main text, and supplement with 4 figure