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16. Structural and Luminescence Properties of (Gd 1−x Y x) 2 O 3 Powders Doped with Nd 3+ Ions for Temperature Measurements.

Author

Aseev, Vladimir, Babkina, Anastasiia, Evstropiev, Sergey, Kuzmenko, Natalia, Sevastianova, Irina, Prokuratov, Denis, and Khodasevich, Mikhail

Subjects
NEODYMIUM compounds, METAL ions, TEMPERATURE measurements, RARE earth oxides, PHOTOLUMINESCENCE
Abstract

Rare earth activated powders are widely regarded as promising candidates for optical thermometry due to their unique photoluminescence characteristics. The paper presents the structural and luminescent properties of crystalline powders of gadolinium and yttrium oxides (Gd1−xYx)2O3, doped with Nd3+ ions, synthesized by the liquid polymer-salt method. The addition of polyvinylpyrrolidone increases the homogeneity of the mixture and ensures high adhesion of the resulting powders. Scanning electron microscopy shows that powders are μm-sized aggregates, which consist of particles with several tens of nanometers in size. A smooth shift of the diffraction peaks of the powders occurs when Gd is replaced by Y without additional peaks. The successive decrease in the lattice constant of the powders from 10.816 to 10.607 Å confirms the existence of continuous solid solutions in the system. The Stark sublevels of the 4F3/2 → 4I9/2 fluorescent band are shifted to 4 nm when Gd is replaced by Y since the strength of the local field has a stronger effect on the inner F-shell of Nd ions in the case of Y. For thermometry, we chose the ratio of the fluorescence intensities between the Stark sublevels 4F3/2(2) → 4I9/2(2) and 4F3/2(1) → 4I9/2(2). The best obtained sensitivity is 0.22% °C−1 for Nd-doped GdYO3 powder in the range of 10–70 °C. This value of temperature sensitivity, together with radiation and excitation lying in the biological window, opens the possibility of using Nd3+-doped (Gd1−xYx)2O3 powders for real-time thermal probing of under tissue luminescence with sub-degree resolution. [ABSTRACT FROM AUTHOR]

Published
2022
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33. New Nanoglassceramics Doped with Rare Earth Ions and Their Photonic Applications

Author

Aseev Vladimir, Nikonorov Nikolay, and Kolobkova Elena

Subjects
Materials science, business.industry, Doping, Nucleation, Crystal growth, Dielectric, Thermal treatment, law.invention, Semiconductor, Chemical engineering, law, Phase (matter), Crystallization, business
Abstract

Glass-crystalline materials (or glassceramics) are heterophase composite materials, usually consisting of a glassy matrix (glass phase) and microor nano-sized dielectric or semiconductor crystals (crystalline phase), or metallic particles distributed in it. Glassceramics are formed by the growth of crystalline phase inside of a glass matrix. The crystal growth can occur as a result of spontaneous thermal crystallization of glass, as in case of heat treatment. For example, there are following typical representatives of the spontaneous crystallization: glasses doped with microcrystals of CdS, CdSe, CdTe, PbS, PbSe (non-linear media) [1-7], glasses doped with semiconductor microcrystals AgBr, AgCl, CuBr, CuCl (photochromic media) [8], glasses doped with dielectric microcrystals Li2O-SiO2 (photoetchable media – FOTURAN TM, FOTOFORM TM, PEG TM [9-11]. The crystal growth can occur as a result of photo-thermo-induced crystallization caused by UV photoirradiation and subsequent heat treatment. In this case, UV radiation generates centers of nucleation and the thermal treatment results in the growth of microcrystals in irradiated area of the glass host. Glasses doped with complicated microcrystals of NaF-AgBr (polychromatic glasses [12] and photo-thermo-refractive PTR glasses [13]) are typical representatives of the photo-thermo-induced crystallization.

Published
2012

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